House of Representatives

On 6 June 2020, Dassen was chosen as Volt's top candidate for the 2021 Dutch general election.^[15] The Volt campaign focused on European, cross-border solutions for climate change, migration, security, and social inequality.^[16][17] Dassen rejected attempts to place him on the left–right political spectrum, dismissing it as "old politics".^[18] Volt won three seats in the election, resulting in Dassen being sworn in as member of the House of Representatives on 31 March.^[19] He stated that his party, being a newcomer, was not open to joining a new governing coalition.^[20] During 2022 budget debates, a motion by Volt and coalition party D66 was carried by the House to appropriate €100 million to provide lunches in school.^[21]

Dassen made various proposals in his first term to lower corruption and raise trust in the Dutch political system. In September 2021, Dassen and fellow members of parliament successfully called through a motion, which was adopted by the House, for a two-year period during which cabinet members could not fill a lobbying position following the end of their term. It was in reaction to recommendations by GRECO and to Minister Cora van Nieuwenhuizen stepping down to work as an energy lobbyist.^[22] Dassen launched a plan with independent politician Pieter Omtzigt in May 2022 to combat corruption among cabinet members and other high-ranking government officials. Their proposal included the expansion of the integrity rules, the introduction of a code of conduct and an authority that enforces it, and the creation of a lobby register that includes meetings.^[23] A motion to introduce the register was carried, but Minister of the Interior and Kingdom Relations Hanke Bruins Slot refused to execute it.^[24] De Volkskrant reported that some of the other proposals of Omtzigt and Dassen were used by Minister Bruins Slot in her bill for a two-year lobbying ban for former cabinet members. The sanctions they had suggested in case of breaching the rules, however, were not included.^[25] Furthermore, Dassen suggested together with Gert-Jan Segers (CU) that trust in the Dutch political system should be increase by strengthening the House's ability to gather information and by raising the number of seats in the House from 150 to 200.^[26] Dassen presented a policy paper on political reform with Segers's successor – Mirjam Bikker – in August 2023. It contained three plans: to increase the size of the House from 150 to 250 seats, to involve the parliament earlier in bills initiated by the cabinet, and to organize more debates on long-term issues such as the effects of artificial intelligence (AI). Dassen argued the responsibilities of members of parliament had grown, partly due to social media.^[27]

During Dassen's tenure as caucus leader, the party suspended House member Nilüfer Gündoğan from its caucus following allegations of unacceptable behavior. When she was definitively expelled in February 2022 after an investigation, Gündoğan filed a criminal complaint for defamation against Dassen, Volt, and the accusers.^[28] A judge determined that the expulsion had been unjust, and Dassen subsequently apologized to Gündoğan but later stated that the conflict could only be resolved after the withdrawal of her criminal complaint.^[29][30] Her expulsion was finally reinstated in March following a vote by the caucus, in which Dassen supported the move calling their relationship "permanently broken".^[31][32] The conflict caused Dassen's approval rating among Volt voters to drop from 96% to 74% according to a poll by EenVandaag and Ipsos.^[33] An appellate court ruled in 2023 that the expulsion had been correct, reversing the lower court's decision.^[34]

When the collapse of the fourth Rutte cabinet triggered a snap election for November 2023, Dassen indicated his intention to become lead candidate once again. Volt's board nominated him for the post and the party's members affirmed the decision with 98% in support.^[35][36] At the party conference, Dassen said radical choices are necessary to mitigate climate change and to reform the Dutch tax system. He advocated for replacing all government benefits by a limited basic income that would later be expanded to a true universal basic income. He also campaigned on a cancellation of debts by the government for those struggling with problematic debts.^[37][38]