Berlusconi lawmakers pull out of Italy coalition

"The conditions for continuing our cooperation with this government no longer exist," Paolo Romani, chief senator for Berlusconi's Go Italy (Forza Italia) party, said in a message on Twitter.

The move will not bring down the government as a group of former Berlusconi loyalists earlier this month broke away from the scandal-tainted ex-premier to form their own party.

The New Centre-Right group led by Deputy Prime Minister Angelino Alfano has said it will stay in the coalition with Prime Minister Enrico Letta's centre-left Democratic Party even if Berlusconi is expelled.

Letta's government will now have a much slimmer majority in the Senate of around 10 senators, while it will continue to enjoy strong support in the lower house because of many centre-left lawmakers.

Alfano's party accounts for about 50 parliamentarians.