MILAN — Former Italian Premier Mario Monti came out Tuesday against a constitutional referendum on which the government’s current leader has staked his future, lending weight to the “no” campaign seeking to force early elections.

Premier Matteo Renzi has said he would resign if the referendum fails, and opposition politicians and dissenters in Renzi’s own Democratic Party have come out strongly against the ballot question in a bid to challenge his nearly three-year-old government.

Renzi has been campaigning hard to pass the measures, which he says will simplify bureaucracy and make the country more competitive. Monti’s unexpected swipe came as the Italian premier was being feted in Washington by President Barack Obama for the last state dinner of his presidency.

At a joint news conference with Renzi, Obama said the U.S. supported the referendum, “because we believe that it will help accelerate Italy’s path towards a more vibrant, dynamic economy, as well as a more responsive political system.”

Renzi said that he fully expected that the “yes” vote would win, but added, “I don’t believe there will be cataclysms in the case that no wins. But to avoid doubts, I prefer to do everything to win the referendum.”

Monti said in an interview published Tuesday in Corriere della Sera newspaper that the reforms proposed in the Dec. 4 referendum do not go far enough and he downplayed the risk of major political and economic problems in case the ballot question fails. Monti’s popularity plummeted after his 2011-2013 term at the head of a government of technocrats, but he remains influential abroad.

“If the ‘no’ wins, foreign investors won’t disappear. And if ‘yes’ wins, democracy won’t disappear. And the EU, which never asked for these constitutional changes, can rest assured Italy doesn’t risk, as was the case five years ago, to bring down the euro,” Monti said.

Monti said that the Renzi government has used previous measures like fiscal breaks and payroll tax bonuses “to lubricate public opinion. I thought about it a lot, and I decided that to vote ‘yes’ in the referendum would be voting ‘yes’ to keeping Italians dependent on this sort of state providence.”

Political analyst Wolfango Piccoli cast doubt on Monti’s position that rejecting the reforms would not cause major political and economic troubles, but said that it nonetheless, “could further limit the ability of the ‘yes’ camp to play the ‘fear factor’ card.”

“Monti’s denial of the negative consequences of a ‘no’ should be seen as an attempt to gloss over the one factor that has likely prompted the former PM to advocate a rejection of Renzi’s reform plans: The two men’s famously strained personal relationship,” said Piccoli, co-president of the Teneo Intelligence consultancy.

Former Premier Massimo D’Alema of the Democratic Party also has come out against the referendum, along with the head of the opposition 5-Star Movement Beppe Grillo, former Premier Silvio Berlusconi and Northern League leader Matteo Salvini.