Socialist Party leader Lilian Marijnissen has announced she is quitting as an MP after the party’s disappointing result in last month’s parliamentary elections.

The SP delegation shrank from nine seats to five, having lost six MPs at the previous election 18 months earlier.

Marijnissen, 38, succeeded Emile Roemer in December 2017 and gained a reputation as one of the best debaters in parliament, but she was unable to stem the decline of the SP since it won 25 seats with 16.5% of the vote in 2006.

Her seat will be taken up by Sarah Dobbe, who was sixth on the SP’s list of candidates for the November 22 edition.

In a post on X, previously known as Twitter, Marijnissen said it had been an “honour to represent the people”, but in the light of the election result she accepted that the party “needed a new face”.

“Ultimately it is not politicians, but people who change the world,” she wrote. “The fight goes on and we need a strong SP more urgently than ever.”

Het was een eer om volksvertegenwoordiger te zijn. pic.twitter.com/irhZfeiBhN

— Lilian Marijnissen (@MarijnissenL) December 9, 2023

Her father, Jan Marijnissen, a former factory worker, led the party from 1989 until 2008 and was one of its first two MPs in 1994.

Lilian appeared on campaign posters in the 1990s, sitting on the front of her father’s bike, and was elected to Oss city council for the SP in 2002 as a 16-year-old, even though she was too young to take up her seat.

She studied political science in Nijmegen and Amsterdam and worked for AbvaKabo, a trade union for civil servants, before being elected to parliament for the first time in 2017.

Pieter Omtzigt, who worked closely with Marijnissen’s colleague Renske Leijten to expose the childcare benefits scandal that led to the resignation of Mark Rutte’s third cabinet, said: “We will miss your will to fight for people’s real problems in parliament.”

Frans Timmermans, leader of the left-wing alliance GroenLinks-PvdA, described her as a “powerful advocate of the case for the left,” while Geert Wilders of the far-right PVV said she was “brilliant, despite all our political differences”.