Allies of Silvio Berlusconi have stepped up warnings that they would bring down Italy's unstable ruling coalition if centre-left legislators refuse to delay a hearing over expelling the former prime minister from parliament.
A cross-party Senate committee, which is deciding whether Berlusconi should be stripped of his seat in the upper house following a conviction for tax fraud last month, resumes talks at 6pm GMT on Tuesday after an initial meeting on Monday.
Tensions have already flared, with Francesco Nitto Palma, a senator from Berlusconi's People of Freedom party (PDL), accusing centre-left members of the committee of "an act of war" by insisting on moving ahead swiftly with the hearings.
The committee's first meeting on Monday saw a day of tactical skirmishing as Berlusconi's centre-right People of Freedom party (PDL) sought to put off a decision on their leader's political future pending an appeal to the European Court of Human Rights.
However, members from the centre-left and the anti-establishment 5-Star Movement have rejected the call, which could delay a decision on Berlusconi's future by months, and are expected to overrule the PDL and press on with the hearing.
Renato Brunetta, PDL floor leader in the lower house, said the attitude was "unacceptable" and risked precipitating a crisis when they meet again on Tuesday.
"The signals coming out of the committee point to a brick wall," he told Italian television.
"If that's what happens I don't think we can talk about there being a majority backing the government," he said.
Berlusconi, convicted by Italy's top court last month of being at the centre of a tax-fraud conspiracy at his Mediaset television empire, could not be expelled without a full vote on the floor of the upper house.
So far the PD has insisted that Berlusconi cannot remain in parliament after Italy's top court convicted him of being at the centre of a vast tax fraud scheme at his Mediaset television empire.
The PDL says Berlusconi, sentenced to four years in jail, has been targeted unfairly by left-wing magistrates, and accuses the PD of using judicial tactics to eliminate a rival it has been unable to defeat politically.
With Italy still straining to contain its €2tn euro public debt, the Berlusconi issue has also impeded Prime Minister Enrico Letta's efforts to reform the eurozone's third largest economy, causing worries that extend well beyond Italy's own borders.
Financial markets have been increasingly on edge as political tensions escalated, pushing up government borrowing costs ahead of Thursday's auction of medium-term bonds.