The main reason for the motion is the loss of signatures and the distrust it has caused, PS deputy faction leader Jani Möderndorfer said after filing the motion, expressing his expectation for the proposal to be backed by a majority in parliament.

The deputy faction had discussed the loss of signatures with parliamentary Speaker Gregor Virant and Interior Minister Vinko Gorenak. "Suspicions have remained unanswered on the part of the Interior Ministry," Möderndorfer said.

Having reviewed documents related to the case, the party established an instance of personal and objective responsibility, which Möderndorfer said meant the minister should have stepped down himself.

The motion is meant "as a lesson and so that people will continue to believe in democratic procedures and trust in the institutions of the National Assembly and the government," the PS official said.

The deputy group also accused the minister of attempting to thwart the referendum initiative by wilfully delaying the procedure to inform the parliament and the referendum proponents of whether the initiative met the legal requirements.

That way, the PS said, the minister prevented the proponents from supplementing their request within the deadlines envisaged by law, which resulted in the initiative being rejected in what was an attempt to deny citizens the right to referendum.

The motion was backed by 27 PS deputies, which did not mean that other deputy faction would not join in by the end of the procedure, Möderndorfer said.

"Each deputy must reflect on the matter and take a stand free from political ideas, be it within the coalition, or in the sense that somebody needs to be protected," he said.

Coalition Democrats (SDS), New Slovenia (NSi) and the People's Party (SLS) said today they would not support the no-confidence motion, while the Pensioners' Party (DeSUS) announced already last week they would vote against. Citizens' List (DL) said they would wait until all investigations into the loss of signatures are complete.

The opposition Social Democrats (SD) meanwhile announced support for the interpellation, pointing to the minister's objective responsibility at best and a "premeditated act" at worst.

Gorenak would not comment on the motion today on the grounds that he must first read it, but he had reiterated on several occasions before that the Interior Ministry was not responsible for the incident.

Speaking in parliament today, Prime Minister Janez Janša labelled the loss of signatures a scandal that should not have happened. But he warned against fingers being pointed before responsibility is established.

This is the 29th "interpellation" motion, as a vote of no-confidence against a minister is called in Slovenia, since independence. Gorenak is the fifth interior minister to face such a motion.

So far, only two interpellations have succeeded, whereas some ministers resigned even before it came to the vote in the National Assembly.