- Italian Prime Minister Giuseppe Conte's coalition government was plunged into turmoil by the withdrawal last week of former premier Matteo Renzi's Italia Viva party.
- Conte - now on the ropes - will seek support with lawmakers ahead of a crucial vote in the upper Senate on Tuesday.
- Conte's government no longer controls the upper chamber after Renzi withdrew Italia Viva's 18 senators.
Italian Prime Minister Giuseppe Conte was due to address parliament's lower house on Monday at the start of a make-or-break week in a crisis that could bring down his government.
Against the backdrop of a coronavirus pandemic that sparked fresh restrictions at the weekend, Conte will seek a show of support with lawmakers ahead of a crucial vote in the upper Senate the following day.
His coalition government, in power since September 2019, was plunged into turmoil by the withdrawal last week of former premier Matteo Renzi's Italia Viva party.
Conte was to speak at midday to the Chamber of Deputies, where his coalition partners including the Democratic Party (PD) and Five Star Movement (M5S) have a majority of support.
The real test will come on Tuesday, however, when he addresses the Senate and faces what will effectively be a vote of confidence.
Conte's government no longer controls the upper chamber after Renzi withdrew Italia Viva's 18 senators, depriving the premier of an automatic majority in the 321-seat house.
"We are working to ensure that the attempt to bring down the government tomorrow is foiled. We are convinced that we will succeed," said PD deputy leader Andrea Orlando.
But the outcome of the Senate vote, and its consequences, are very uncertain.
Conte has been trying to win the support of opposition lawmakers but is struggling.
Renzi, meanwhile, has said his party will abstain - making it easier for the government to win the vote, but risking further turbulence.
If Conte and partners cannot show they have a solid parliamentary majority, the premier is expected to resign, opening up three main scenarios.
The PD and M5S could patch things up with Renzi, and form a reshuffled government, with or without Conte at the helm.
Otherwise, there could be a grand coalition government, probably led by a non-partisan figure, or snap elections, which would be expected to hand victory to right-wing opposition parties.
Renzi had for weeks been criticising Conte's handling of the pandemic, his plans for a 200-billion-euro European Union recovery fund and his personal governing style.
Italy imposed a partial lockdown across several regions on Sunday and tightened restrictions in others in a bid to control a Covid-19 pandemic that has claimed more than 82,000 lives and devastated the economy.