Geert Wilders has nominated the head of a committee that advised the Dutch government two months ago to limit migration as one of two leaders of the next stage of talks to form a new government.

Richard van Zwol chaired the Demographic Development Commission 2050, which warned the government in January that migration needed to be curbed as the Netherlands became “busier, greyer and more diverse” over the next 25 years.

However, the committee favoured moderate growth of 1 to 2 million inhabitants, which would the population to just under 20 million, over Wilders’s preferred option of cutting immigration to zero.

Wilders named Elbert Dijkgraaf, a professor of economics who sat in parliament for the orthodox Christian party SGP until 2018, as his other lead negotiator. They are expected to be given a maximum of eight weeks to produce a outline policy document for the new government to implement.

The pair are expected to be appointed by MPs later on Wednesday at the end of a debate on the last round of cabinet negotiations under the leadership of Kim Putters, former director of the Netherlands Institute for Social Research.

The nomination of Van Zwol, a former chair of the Christian Democrat (CDA) research department who has been a member of the Council of State since 2017, came as a surprise to party leader Henri Bontenbal.

No contact

Bontenbal said he only learned of the proposal shortly before MPs began debating Putters’s report, raising concerns about how the four parties who are trying to form a cabinet will recruit ministers. “Is this going to go through the parties, or by approaching members of the cabinet individually?” he asked.

The CDA is one of several parties, along with D66 and GroenLinks-PvdA, who have said they will not endorse party members who take seats in a cabinet supported by Wilders’s far-right PVV party.

SGP leader Chris Stoffer also said he had not been told before the debate that Dijkgraaf had been approached.

Wilders said he and the other three party leaders – Dilan Yesilgöz of the VVD, Pieter Omtzigt of NSC and Caroline van der Plas – had made the “greatest political sacrifice” by agreeing to sit in parliament rather than the cabinet table.

But he denied that the parties had chosen an “extra-parliamentary” format in order to prevent him becoming prime minister. “It’s not the case that everyone round the table felt I shouldn’t be prime minister,” he said.

“Tough” negotiations

Wilders said the four leaders faced a “very tough” round of negotiations to ensure that “the outcome in the outline agreement is acceptable to our voters.”

Putters recommended a cabinet with an even split of ministers appointed from within the four parties and others drawn from outside, including members of other parties in parliament.

He said a less detailed agreement between the four parties would reduce the chance of the cabinet falling apart over the details. The last government collapsed when the coalition partners were unable to agree on how to restrict the number of asylum seekers who could join their families in the Netherlands.

Omtzigt, who walked away from the previous round of talks, said the negotiations would “not be easy”, but expressed enthusiasm for the format of an “extra-parliamentary programmatic cabinet” that will base its legislation on a framework agreement negotiated by the four parties.

“There are four very different manifestos, so we have some serious talking to do,” Omtzigt said.

10-point plan

Yesilgöz said the composition of the cabinet should be a “reflection of the four parties”, but ministers could be appointed from anywhere. “If you feel a vocation for it and you want to do your bit towards the stability of the Netherlands, we welcome you,” she said.

She also said that the 10-point list of subjects that would form the basis of the government’s programme was not exhaustive, after D66 leader Rob Jetten questioned the absence of topics such as education, climate change and aid to Ukraine.

Van der Plas told a meeting of the BBB on Monday that the party would have to make concessions, but could also “achieve a great deal”. “We need to make progress in the national interest,” she said.