Italian Prime Minister Enrico Letta’s coalition government said yesterday it would call a confidence vote on its 2014 Budget, a move that will give the first clear proof of its strength since Silvio Berlusconi’s party split this month.

Confidence votes, which limit the scope for time-consuming amendments, are regularly called to speed up legislation in Italy and Letta is almost certain to win with the backing of rebels who split off from Berlusconi’s centre-right party, now rebranded under its original name Forza Italia.

But the motion in the Senate heightens tension ahead of a vote to expel Berlusconi from Parliament this week and is likely to cement the split between Forza Italia and Letta’s coalition of left and right formed after February’s deadlocked elections.

“The confidence vote is necessary not only to guarantee a quick approval (of the Budget law) but also to verify... the trust between the government and its parliamentary majority,” said Parliamentary Affairs Minister Dario Franceschini.

Berlusconi, facing almost certain expulsion from Parliament following a conviction for tax fraud, last month failed to bring down the government and has sounded increasingly hostile ahead of a Senate vote this week to approve his removal.

The 77-year-old billionaire has promised to break with the government and go into open opposition if Letta’s centre-left Democratic Party votes for his removal from Parliament as it has promised and rallies by supporters are planned in central Rome during the vote.

His threat to pull out of the coalition prompted a party split, which has left 30 centre-right senators and 27 deputies supporting the government.

The Budget, a compromise Bill worked out after much wrangling between the coalition partners, includes some tax cuts on labour costs and deficit-cutting measures, but the European Commission has warned it may not respect debt reduction targets.

A vote is currently scheduled for today but may be delayed. The vote is just one part of the Budget’s passage through Parliament, which must be completed by the end of the year.