LONDON — Geert Wilders, the anti-Muslim politician who has campaigned for a tax on head scarves and a ban on the Koran, seemed poised Thursday to emerge as a prominent player in a new minority government in the Netherlands.

While the outspoken and populist Mr. Wilders would not gain a ministerial appointment, the proposed deal to form the government would make him one of the most influential politicians in the Netherlands.

Led by Ivo Opstelten, a former mayor of Rotterdam who was appointed mediator for the next stage of negotiations, the discussions on forming a government are expected to take about three weeks.

They follow elections in June in which Mr. Wilders’s Freedom Party increased its number of seats in the 150-seat Parliament to 24, from 9. The center-right Liberal Party, led by Mark Rutte, which emerged as the largest party in Parliament, hopes to enter a coalition with the Christian Democrats, who led the last government.

Advertisement Continue reading the main story

But the two parties would have to rely on Mr. Wilders to get important legislation through, including austerity cuts expected to total about $24 billion. If the deal comes to fruition, Mr. Wilders will follow in the footsteps of Denmark’s populist, anti-immigration Danish People’s Party, which has stayed out of government but supported a minority center-right administration.