Premier Romano Prodi was poised to quit on Thursday night after a Senate confidence vote produced a widely expected defeat for his 20 month-old center-left government.

Prodi's administration, which has had a wafer-thin majority in the 315-seat upper house ever since it came to power, lost the crucial test by five votes.

As expected, key centrists in his eight-party coalition voted against the government, finally pulling the plug on an alliance which was deeply divided on a wide range of issues.

The government called confidence votes in the Lower House and Senate after the small Udeur party withdrew its support following the resignation of its leader, Justice Minister Clemente Mastella.

The premier, who is obliged to quit after losing a confidence vote, was shortly expected to pay the customary call on President Giorgio Napolitano to hand in his resignation.

Editor: Yan