Italian centre-left leader Matteo Renzi unveiled his Cabinet yesterday after formally accepting the mandate to form a government he said would remain in place until 2018.

Renzi confirmed that OECD Chief Economist Pier Carlo Padoan would take over the key economy ministry portfolio in the 16-minister Cabinet. The new premier said his government would begin work immediately.

We’re aiming to get started on things that need to be done

“We’re aiming to get started on things that need to be done from tomorrow morning,” he told reporters after a two-and-a-half hour meeting with President Giorgio Napolitano.

The government is expected to be sworn in formally at 11.30am today before a vote of confidence in Parliament on Monday.

Renzi, who forced out his party rival Enrico Letta last week after attacking the slow pace of economic reforms, will govern with the same cross-party alliance that hampered his predecessor’s efforts. Six of the new ministers were part of Letta’s Cabinet; three are from the small centre-right NCD party on which Renzi’s parliamentary majority depends.

At 39, Renzi will be Italy’s youngest-ever prime minister, and the third in a row to reach office without winning an election. Opinion polls suggest many Italians are concerned about the lack of a mandate from voters, and questions about how he gained office could limit Renzi’s ability to push through unpopular reform measures.

Renzi, leader of the centre-left Democratic Party (PD), has sketched out an ambitious agenda, promising to tackle electoral and constitutional reform, make the labour market and tax systems more efficient and overhaul the bloated public administration all within four months.

Napolitano said that structural reforms to the Italian Constitution and the economy, only just emerging from its longest slump since World War II, had to be tackled immediately.

In notable changes to the Cabinet line-up, Angelino Alfano kept his post as interior minister, but will no longer have the title of deputy prime minister. That suggests Renzi ruled out giving him a post that could challenge his own authority.

Foreign Minister Emma Bonino, a well-known figure outside Italy, leaves the government to be replaced by Federica Mogherini, a defence and foreign policy specialist in the PD.

Padoan, a respected former International Monetary Fund official, will be the third technocrat in a row at the ministry, the key contact point with the European Central Bank and EU partners and an important factor in maintaining foreign investor confidence.

As head of the OECD’s economics department, Padoan has called for aggressive easing from the European Central Bank and was an early critic of tough budget cutbacks in the euro zone’s weakest economies as they struggled with excessive debt.

A poll yesterday by the SWG polling institute posted a dip in support for the PD, to 29.9 per cent from 32.2 per cent a week earlier, while support for former Prime Minister Silvio Berlusconi’s Forza Italia rose to 21.8 per cent from 20 per cent.

The survey showed 27 per cent saw Renzi as a leader capable of giving a future to Italy, more than any other potential rival on the list.

But that vote of support was still outscored by the 30 per cent who picked “none”.