The far right PVV had put forward making owning a copy of the Koran an offence punishable by five years in jail during the cabinet formation talks earlier this year, NSC leader Pieter Omtzigt told a television talk show on Sunday.

Without mentioning the party by name, Omtzigt said the negotiations at times were about “very difficult things”.

“They had to do with a party which drew up draft legislation which would put a five year jail term on owning a copy of the Koran,” he said. “That was on the table.”

His comment was later disputed by Caroline van der Plas, leader of the smallest coalition party BBB, who said on social media the measure had never been part of the discussions. “It was a proposal from years ago and nothing was done with it,” she said.

Omtzigt responded to say the measure was withdrawn on January 8 when the four party leaders first met in De Zwaluwenberg country estate to continue their negotiations. He also pointed out that Ronald Plasterk had started the coalition talks on December 13.

In that first week, he said, the four parties had had “long and intense” discussions about the rule of law.

On January 8 PVV leader Geert Wilders told parliament he was abandoning three pieces of draft legislation, all of which had been criticised in harsh terms by the Council of State for violating constitutional rights.

One of the proposals called for prison terms of up to five years to be imposed for “Islamic activities” such as possessing a Koran or attending a Muslim school.

The move was seen at the time as a concession to Omtzigt’s NSC party and the right-wing liberal VVD, who were reluctant to join a cabinet with the PVV because of Wilders’s approach to the rule of law.

Wilders has not commented on the spat between Omtzigt and Van der Plas.