POLICY PAPER Sarah de Lange The 2025 Dutch elections: why the D66 trumped the GL–PvdA alliance On 29 October 2025, Dutch citizens voted in elections ­to the House of Representatives(Tweede Kamer) for the third time in four years. ­Although the GreenLeft–Labour Party(GroenLinks-PvdA or GL-PvdA) alliance had ranked second in the polls when elections were called in June, it finished fourth on election day itself. 1 Its vote share declined from 15.8% in 2023 to 12.8% in 2025, heading towards the parties’ lowest ever combined result of only 10% in 2021. The alliance also lost its position as leader of the cosmopolitan, progressive bloc to D66, which won the election with 16.9% of the vote. In the wake of such a disappointing result, party leader Frans Timmermans resigned on election night. This report analyses why the GL-PvdA alliance – and the Left more broadly – underperformed in 2025. It argues among other things that strategic voting, weak leadership appeal and ineffective campaign messaging contributed to the defeat. Off to a good start? GL-PvdA performed well in the 2023 elections, but the most consequential outcome was the victory of Geert Wilders’ far-right Party for Freedom(PVV), which became the largest party with 23.5% of the vote. Together with the People‘s Party for Freedom and Democracy(VVD), New Social Contract(NSC) and the Farmer Citizen Movement(BBB), it formed a majority government after protracted negotiations dragged out for 223 days. The cabinet, led by non-partisan Prime Minister Dick Schoof and excluding party leaders, was plagued by internal conflict and repeated concerns about its respect for the rule of law. The government collapsed on 3 June 2025, after only 337 days in office, when the PVV withdrew its support, claiming that its coalition partners were unwilling to endorse additional measures to curb the influx of asylum seekers, including a proposal to close the borders to all applicants. New elections were called for October because of organisational constraints. Under the Schoof I cabinet, GL-PvdA was the largest opposition party, having won 15.8% of the vote in 2023. It was considerably larger than other left-wing or progressive opposition parties, such as D66(6.6%), the Socialist Party (SP, 3.2%), DENK(2.4%), the Party for the Animals(PvdD, 2.3%), and Volt(1.7%). This presented the alliance with a clear opportunity to position itself as the main alternative to a conservative-nativist government coalition. In addition, socio-economic issues such as health-care affordability and housing shortages remained highly salient, seemingly providing favourable conditions for a strong campaign in 2025. The 2025 Dutch elections 1

But the alliance failed to take advantage of these opportunities. Its support remained stable at around 15–16% throughout 2024 and early 2025, rising to 17% only shortly before the government’s collapse. Other left-wing parties also made only modest gains, with limited growth for D66, the PvdD and the SP. Voters who were fed up with the government instead increasingly turned to the Christian Democratic Appeal (CDA), which had recovered strongly under popular leader Henri Bontenbal and briefly overtook GL-PvdA in the polls. Election campaign and results The campaign, which kicked off in September 2025, was dominated by the immigration issue. The issue had also been instrumental in bringing down the government. The right-wing parties pushed it for all they were worth, exacerbated by violent anti-immigration protests in The Hague and Amsterdam. Televised election debates likewise centred on migration, as the far-right frequently framed socio-­ economic issues such as housing in terms of immigration, emphasising the pressure that asylum seekers, immigrants and international students allegedly impose on the housing market. Polls showed that CDA, D66 and JA21 gained ground during the campaign, while GL-PvdA, PVV and VVD lost it, but even as late as three days before election day, between 50% and 80% of voters were undecided. The 2025 elections proved to be among the most volatile in Dutch history, although voter shifts occurred mainly within three ideological blocs: a left-wing bloc(DENK, GL-PvdA, PvdD, SP, Volt), a right-wing bloc(BBB, CDA, NSC, SGP, VVD), and a far-right bloc(FvD, JA21, PVV). D66 occupies a distinctive position within this system, combining a ­centre-right socio-economic profile with a cosmopolitan-­ progressive outlook, which in principle would enable it to attract voters from both sides. 2 GL-PvdA performed poorly, its share of the vote falling from 15.8% to 12.8% and losing five parliamentary seats. This marked the alliance’s second-worst result ever, only marginally better than in 2021. Only 60% of its 2023 voters remained loyal. The largest share of defectors(22%) switched to D66, while 6% abstained. Smaller shares of voters were lost to the CDA(3%), the PvdD(2%), the VVD(1%) and the SP(1%). On the other hand, GL-PvdA did attract some new voters, with 5% of its 2025 voters coming from D66, 3% from the SP, 2% from NSC, and 2% from the PvdD, as well as a sizeable group of previous non-voters(6%), who probably ­included many first-time voters. With the exception of DENK, which remained stable at 2.4%, all the left-wing parties lost ground. This shrank the left-wing bloc to just 20% of the vote, its lowest level since the introduction of universal suffrage in 1919. It was also the smallest share in Western Europe, where on average left-wing parties have typically retained around one third of parliamentary seats: in the Netherlands they now hold only one fifth. 3 However, several scholars include D66 in their assessments of the size of the left-wing bloc, citing its progressive, cosmopolitan agenda and appeal to left-wing voters. On this basis, the Seat share GroenLinks, PvdA, and GroenLinks-PvdA, 1994–2025 60 Figure 1 Percent 50 40 30 20 10 0 1995 2000 2005 GL PvdA GL-PvdA 2010 2015 2020 2025 The 2025 Dutch elections 2

cosmopolitan-progressive left can be regarded as having performed better in 2025 than in 2023, the inclusion of D66 raising its number of seats from 47 to 56. 4 D66’s strong performance lends some support to this view: the party nearly tripled its representation, rising from 9 to 26 seats, with its main gains coming from GL-PvdA. While only 25% of its 2025 electorate had voted for D66 in 2023, 20% had previously supported GL-PvdA, with additional voters coming from NSC (13%), the VVD(11%) and former non-voters(9%). Overall, however, D66 drew more support from the(far-)right(35%) than from the left(23%), which calls into question the justification of including its vote share as part of the left-wing bloc. Voter realignment was equally pronounced on the right. NSC, the maverick party founded shortly before the 2023 elections and entering parliament with 20 seats, rapidly lost support after engaging in coalition talks with the PVV. Many supporters felt the party had compromised its commitment to the rule of law by cooperating with Wilders. As a result, NSC’s support had fallen below 5% by autumn 2025, well before the Schoof government took office. Its parliamentary survival was already uncertain when elections were called. Former NSC voters defected primarily to the CDA(28%), followed by D66(18%), the VVD(11%) and JA21(10%), while 11% abstained. The VVD, buoyed up by inflows from dissatisfied NSC and PVV voters, managed to limit its losses. Although it lost voters to the more centrist D66(13%) and the CDA(12%), these losses were offset by gains from more right-leaning voters. However, most former NSC voters moved to the CDA, which mounted a strong recovery after its worst ever result in 2023, increasing its vote share from 3.3% to 11.8% by emphasising stable leadership and core norms and values. Within the far-right bloc, the PVV emerged as the main loser, shedding 11 seats. Most dissatisfied supporters shifted to JA21 and the Forum for Democracy(FvD). JA21, ideologically close to the PVV but more willing to compromise, expanded from one to nine seats, while the more radical FvD grew from three to seven seats. As a result, the farright bloc as a whole gained one seat, thereby becoming the largest in Dutch politics. The PVV nevertheless retained a substantial share of its 2023 voters, most of whom blamed coalition partners for preventing Wilders from delivering on his policy promises. Composition of Dutch Parliament Figure 2 Total: 150 seats −6.8 +10.6 −1.0 −3.0 +8.5 −12.5 +5.2 +2.3 −2.0 0.0 +0.2 −0.2 −1.3 −0.1 +0.9 −0.6 Share 16.9% 16.7% 14.2% 12.8% 11.8% 5.9% 4.5% 2.7% 2.4% 2.3% 2.1% 1.9% 1.9% 1.4% 1.1% 0.4% Seats 26 26 22 20 18 9 7 4 3 3 3 3 Party D66 PVV VVD PvdA GLCDA JA21 FvD BBB Denk SGP PvdD SP 3 2 1 – CU 50+ Volt NSC * 2025 Vote share compared to the 2023 election The 2025 Dutch elections 3

Why the D66 trumped GL–PvdA Strategic voting In the 2023 elections, the GL–PvdA alliance finished second largely because it was perceived as the main challenger to the PVV and the VVD. Around half of its total 15.8% of voters supported the alliance for strategic reasons, hoping it would become the largest party and thus lead coalition negotiations, or at least be indispensable to a broad mainstream coalition. 5 Many of these strategic voters also viewed D66 as an acceptable alternative. As a result, GL–PvdA’s strong reliance on strategic voting in 2023 made it particularly vulnerable to the emergence of another progressive party as principal challenger to the PVV in 2025. This possibility did indeed materialise early in the 2025 ­campaign, when D66 quickly assumed the role of main challenger. From the outset of the campaign in September, party leader Rob Jetten dominated media coverage. His ­visibility was boosted, somewhat improbably, by a winning streak on the popular television quiz show The Smartest ­Human, starting on 11 September, but other factors included an attack on the D66 party headquarters by far-right activists on 20 September and his unexpected participation in a high-­ profile televised debate on 12 October after Wilders withdrew for security reasons. 6 Leadership popularity Jetten’s media exposure boosted his popularity. His favourability ratings rose and his social media following surged to 423,000 within two weeks, approaching that of Frans Timmermans. 7 Crucially, Jetten was also more popular among prospective GL–PvdA voters than Timmermans himself, who recorded the lowest score of all party leaders among their own supporters. Preliminary data from the Dutch Parliamentary Election Study(DPES) indicate that GL–PvdA voters registering low approval of Timmermans and high evaluations of Jetten were particularly likely to defect to D66. Leadership thus played a decisive role in the 2025 elections, reinforced by strategic considerations. As D66 surged in the polls, it appeared increasingly likely to enter government, whereas the VVD consistently ruled out governing with GL–PvdA, portraying the alliance as too radical. Campaign framing Jetten also benefited from a campaign approach based on optimism and momentum. Drawing on elements associated with Obama-style campaigning, D66 emphasised hope, positivity and a»can-do« ethos rather than making detailed policy proposals. The party deliberately downplayed traditional issues such as climate change, which were still strongly ­associated with GroenLinks, and instead promoted a form of»progressive patriotism«. This combined a more centrist, and in some respects even centre-right, stance on immigration with strongly pro-European positions. D66 acknowledged the influx of asylum seekers as a societal problem requiring firm solutions, endorsed a Canadian-style immigration model and advocated the externalisation of asylum procedures outside the EU. Symbolically, Dutch and EU flags were displayed side by side at party rallies. This strategy proved effective in attracting even voters who had supported(far-)right parties in 2023, while Jetten also presented himself as the principal opponent of Wilders, promising to end the»Wilders era« and calling on democratic parties to unite behind him. This dual message resonated with both centrist and progressive voters. By contrast, GL–PvdA struggled to run a campaign that could be equally compelling. Although the alliance adopted an economically left-wing and culturally progressive platform, it got in line with the broad rightward shift on immigration, setting migration targets and proposing restrictions on labour migration. 8 Its campaign emphasised housing and health care, but lacked a clear long-term vision. Furthermore, Timmermans often addressed these issues in a technocratic way. More generally, the campaign appeared unfocused and backward-looking, stressing the preservation of past achievements rather than putting ­forward a persuasive vision for the future. Taken together, the lack of leadership appeal and the framing of the campaign contributed significantly to GL–PvdA’s electoral losses in 2025. Going forward Despite GL-PvdA’s severe setback in 2025, especially given that the central aim of the ongoing merger was to consolidate its position as the main challenger to the(far-)right, all is not lost for the alliance. Timmermans has been replaced by Jesse Klaver, former leader of GroenLinks. Klaver is a significantly younger leader with extensive experience heading a more movement-oriented party and confronting the(far-)right from the opposition benches. He is widely regarded as a strong debater and known for his ideological flexibility. Moreover, a minority coalition of D66, CDA and VVD has now formed on the basis of a clearly right-leaning coalition agreement. The agreement contains measures that would weaken social security, impose restrictive migration policies and constitute a more modest approach to climate change, reflecting the strong influence of the VVD 9 on the agreement. GL-PvdA has made it clear that it cannot support these policies, however, and that the coalition would need to change course substantially before the alliance considered backing the minority cabinet. Given the agreement’s rightward orientation overall, a firm oppositional strategy may prove more effective in the coming years than issue-­by-issue negotiations over conditional support. The 2025 Dutch elections 4

Early polling since the agreement suggests that progressive D66 supporters are disappointed with the coalition’s direction, and some indicate a renewed preference for GL-PvdA. More broadly, sizeable groups of left-wing and progressive voters continue to state that they would consider voting for the alliance under the right conditions, suggesting that a future-oriented programme, combined with a coherent campaign could win them back. Particularly promising is GL-PvdA’s strong support among young voters, especially young women, in 2025. This indicates that generational turnover, long seen as a threat in light of PvdA’s aging electorate, may instead turn out to be an opportunity, ­especially if the minority coalition continues to pursue a rightward course. Endnotes , o.b.v. peilingen Ipsos I&O and Verian/EenVandaag , see https://peilingwijzer.tomlouwerse.nl/grafiek_trends.html   der Meer, Tom, and Wouter van der Brug (2024)»Changing Patterns of Party Choice in Dutch Electoral Politics«, in Sarah de Lange et al.(eds), The Oxford Handbook of Dutch Politics(accessed 26 December 2025). 3  https://jacobin.com/2025/11/netherlands-dutch-electionsleft-­defeat 4  https://whogoverns.eu/no-the-far-right-was-not-beaten-in-thedutch-elections/ 5  https://www.ipsos-publiek.nl/actueel/terugblik-tweede-kamer verkiezingen-2025/ 6 https://schermtijdteller.groene.nl/ 7  https://nos.nl/collectie/14002/artikel/2588414-zo-hard-groeiden-­ politici-online-in-de-laatste-campagneweken 8 https://whogoverns.eu/no-the-far-right-was-not-beaten-in-thedutch-elections/ 9  https://stukroodvlees.nl/wie-heeft-de-formatie-gewonnen-en-­ verloren/ The 2025 Dutch elections 5

About the author Sarah de Lange is Professor of Dutch Politics at the Institute for Political Science at Leiden University. Her research agenda centres on new social and political divisions, the associated rise of the far right and the impact of these parties on mainstream parties, policymaking and the functioning of democracy. She is a member of the curatorium of the Dutch Wiardi Beckman Foundation, the think tank affiliated with the PvdA. Imprint Published by Friedrich-Ebert-Stiftung e.V. Godesberger Allee 149 53175 Bonn, Germany info@fes.de Issuing Department FES Regional Office for International Cooperation Democracy of the Future Reichsratsstr. 13/5 A-1010 Vienna Contact Michael Jennewein michael.jennewein@fes.de Editor Margarete Lengger margarete.lengger@fes.de Design pertext| www.pertext.de The views expressed in this publication are not necessarily those of the Friedrich-Ebert-Stiftung(FES) or of the organization for which the author works. Commercial use of media published by the FES is not permitted without the written consent of the FES. Publications by the FES may not be used for electioneering purposes. March 2026 © Friedrich-Ebert-Stiftung e. V. Further publications of the Friedrich-Ebert-Stiftung can be found here: ↗ www.fes.de/publikationen FES Regional Office for International Cooperation The 2025 Dutch elections 6