Italy's justice minister will face a no-confidence vote in the Senate on Wednesday after critics accused him of needlessly releasing dangerous mobsters from jail during the coronavirus lockdown.

Alfonso Bonafede's decision to allow old and ill mafia gangsters to move to house arrest at the start of May sparked an outcry and forced him to backtrack. Some of the highest-profile criminals have already returned to jail.

He freed the most vulnerable inmates to ease overcrowding and lower the virus risk after riots broke out in March among prisoners fearful of catching the disease.

The coalition government, made up largely of the centre-left Democratic Party (PD) and anti-establishment Five Star Movement (M5S), has enough votes in the Senate to save its minister.

But it will be relying on minor coalition member Italia Viva (IV) playing ball. The party, lead by former prime minister Matteo Renzi, has held back from saying whether its 17 senators will vote in line with the government or not.

Prime Minister Giuseppe Conte has warned Renzi that ousting Bonafede would plunge the government into crisis.

Heading to the polls early would not benefit Renzi, whose party is on track to win only 3% of votes, according to opinion polls.

"We don't support the idea of sending this government home, we just want it to get back on track," one of IV's leading figures, Ettore Rosato, told Radio Ettore Rosato Wednesday.