Italy’s new populist coalition was sworn in on Friday as Jean-Claude Juncker, the president of the European Commission, apologised for remarks suggesting that Italians in the south of the country were work-shy and corrupt.

The swearing-in took place in the Quirinale Palace, once the home of popes but now the residence of Italy’s president, Sergio Mattarella, who clashed with the populists during tortuous negotiations to form an administration after three months of post-election deadlock.

Western Europe’s first populist, Eurosceptic government plans to slash taxes, spend billions on increased social welfare measures and demand the reform of EU rules on budgets and migrants.

Giuseppe Conte, a law professor whom Italians had never heard of until 10 days ago, was sworn in as prime minister, along with 18 ministers, five of them women.

Mr Conte will face a stiff challenge in mediating the competing demands of Luigi Di Maio, the head of the anti-establishment Five Star Movement, and Matteo Salvini, who heads the hard-Right, anti-immigration League.