Ventsislav Varbanov, Bulgaria's former agriculture minister in the right-wing government of Ivan Kostov, has left the parliamentary group of the right-wing Blue coalition.

This was announced by parliamentary speaker Tsetska Tsacheva on Wednesday morning.

The motives for the decision were not immediately clear.

Varbanov, who is accused of embezzling funds from the country's agriculture fund between 1998 and 2001, when he held the position of Agriculture Minister, last month filed for the second time a declaration to give up his immunity so that he can clear his name.

"I want my MP immunity stripped so that the trial could continue as that is the only way I could prove that I am not guilty," Varbanov said.

Varbanov's case first entered the court after he gave up his MP immunity in May 2006, when he was an MP from the tiniest right-wing party in Parliament Bulgarian People's Union.

His name came into the limelight at the beginning of April 2006, when the then Bulgarian top prosecutor called for the lifting the immunity of several MPs.

The demands of the chief prosecutor came after the critical reports on Bulgaria's lumbering judiciary by European advisors and by Enlargement Commissioner Olli Rehn.

In a bid to appease Brussels, Bulgaria amended its constitution by cutting the threshold of immunity enjoyed by deputies and giving parliament the right to dismiss the chief prosecutor and heads of the civil and supreme courts.