Silvio Berlusconi also said on Tuesday that his main ally, the Northern League, agreed that quitting the currency would not be good for the country.
Until now, the leader of the League, Matteo Salvini, has not been clear about his view of the euro but pledged last week to rectify the “error” of the single currency.
Berlusconi is hoping to lead the centre-right back to power in the election in March.
He said the common currency should be continued to be handled in the way that the European Central Bank head Mario Draghi has done.
He said: “Salvini is no longer of the idea that we should leave the euro. He has understood that it would be unsustainable for our economy.”
The euro is key in the election discussions as many Italians say the single currency is to blame for the declining economy.
The prospects that some parties could try to pull Italy out of the single market currency has rattled financial markets.