The small Catholic Udeur party has withdrawn its support for Italian Prime Minister Romano Prodi's ruling coalitiony, depriving the government of a majority in the upper house of parliament.

Clemente Mastella, whose Udeur party helped secure a majority after Prodi's government came to power in 2006, told a news conference he favoured snap elections.

"This majority does not exist anymore, this centre left is finished," Mastella said. "We're for elections."

Mastella stepped down as justice minister last week after he and his wife came under investigation in a corruption probe. He had said previously his party would provide "external" support for Prodi's government, but today he said it would no longer do so.

Mastella's party has three seats in the Senate, where Prodi had a majority of two seats.

Prodi could still win key votes with the help of non-elected senators for life, but the loss of the Udeur means that Prodi's coalition no longer has a majority of elected lawmakers in the upper house of parliament.

Picture: Clemente Mastella with Prime Minister Prodi (right).