A junior coalition partner of Slovenian Prime Minister Janez Jansa quit the government on Monday, joining two other parties who defected after he refused to resign over corruption claims.
The Slovenian People's Party (SLS), which has two ministers in government, became the third party to quit the coalition, leaving Jansa's Democrats and their smallest junior partner with 30 seats in the 90-seat parliament.
The Civic List split a month ago after a report by the anti-corruption commission claimed that Jansa had failed to report income. The pensioners party DeSUS quit later.
The conservative premier, who is on trial for corruption charges related to the purchase of armoured personnel carriers for the military, denies any wrongdoing. He has vowed to carry on with a minority cabinet.
The largest opposition party, Positive Slovenia (PS), has filed a no-confidence motion and is discussing a new governing alliance with the defectors from Jansa's bloc and President Borut Pahor's Social Democrats.
A no-confidence vote may take place on Wednesday, the STA news agency said. If PS manages to garner enough support for a new government, it would avert an early elections. A snap poll was held 14 months ago.
The anti-corruption commission published a report in January accusing Jansa of failing to report 210,000 euros (285,000 dollars) in income.
The political crisis has heightened fears that Slovenia's economy could further worsen, forcing the eurozone member to declare bankruptcy.