More than half of people planning to vote for the left-wing alliance of PvdA-GroenLinks this week are doing so for tactical reasons, according to new research for current affairs programme EenVandaag.

A panel survey of 30,000 voters showed 54% would “probably” or “definitely” vote for Frans Timmermans’s list on tactical grounds. Geert Wilders’s far-right PVV was the next biggest beneficiary of tactical voting with 43%.

The research was published the day after an opinion poll by Maurice de Hond suggested Wilders had caught the front runners with a five-seat gain in the last week.

According to De Hond, the right-wing liberal VVD and Wilders’s party are both on course to win 26 seats, followed by PvdA-GroenLinks and Pieter Omtzigt’s new centre-right party Nieuw Sociaal Contract on 23.

De Hond has tended to overstate support for Wilders’s party – on the eve of the last election he polled the PVV on 22 seats, when the actual outcome left them with 17.

Other polls put the PVV in fourth place on around 20 seats, but also have Wilders closing the gap on the front three.

‘Game changer’

Progressive party leaders stepped up their calls for voters to block a right-wing cabinet in the wake of the De Hond poll, which Wilders himself called a “game changer”.

“I don’t want to wake up on Thursday in a country where Wilders is the leader of the largest party,” Timmermans said on X, formerly known as Twitter. “We have a few days left to unite all green, social and progressive voters.”

Ik wil donderdag niet wakker worden in een land waar Wilders de leider is van de grootste partij.

We hebben nog een paar dagen om alle groene, sociale en progressieve kiezers te verenigen.

Kom in actie. Stem GroenLinks-PvdA. pic.twitter.com/B43ub6Di0T

— Frans Timmermans (@F__Timmermans) November 18, 2023

“If the PVV is able to become the largest party, it means a big risk of an extreme right cabinet,” D66 leader Rob Jetten said.

Research published in the Volkskrant at the weekend also showed Timmermans had the most to gain from tactical voting, with 42% of Volt supporters and 40% of those who favoured D66 still considering a switch.

The VVD, led by Dilan Yesilgöz, has the smallest growth potential, with 20% of NSC voters considering a late switch, while both NSC and PVV could pick up votes from the farmers’ party BBB, which has been losing support throughout the campaign.

According to the Volkskrant, 39% of BBB voters are contemplating switching to Omtzigt while 25% could still back Wilders.