Rome, February 16 - Deputy Premier and Interior Minister Angelino Alfano hit back at insults from his former mentor Silvio Berlusconi on Sunday, when he said the ex-premier surrounded himself with "useless idiots".

Alfano, 43, had long been considered Berlusconi's political heir apparent before a painful split last year.

Alfano formed a breakaway group, the New Centre Right (NCD), that kept outgoing Premier Enrico Letta's grand-coalition government alive in November when Berlusconi's revived Forza Italia (FI) party pulled its support shortly before the media magnate was ejected from parliament following a definitive tax-fraud conviction.

"Because of all the kicks it has taken, Forza Italia has gone from having the support of 38% of voters to 22% and if it wants to keep going like this, it can do so," Alfano told a party meeting. "In recent years, Berlusconi has surrounded himself with too many useless idiots". Alfano's NCD is expected to reach an agreement with the leader of the centre-left Democratic Party (PD) Matteo Renzi, who looks poised to form a new government after he torpedoed the administration led by his PD colleague Letta this week.

Berlusconi, meanwhile, has said FI will conduct "responsible opposition" to a Renzi government. Sunday's attack by Alfano came after Berlusconi called the NCD "useful idiots for the left" at an election rally in Sardinia on Friday.

Alfano said those comments made the prospect of future alliances between the NCD and FI "complicated".

Both Alfano and Berlusconi has previously suggested they would be allied the next time Italy goes to the polls. "Berlusconi was unrecognisable to me," Alfano said. "Anger and rancour were never associated with the Berlusconi I knew". Alfano also criticised three-time premier Berlusconi's political record.

He said, for example, that he hoped he could reach an agreement with Renzi for a government that would set off a "march" towards a "liberal revolution" that Berlusconi had failed to bring about.

He also accused Forza Italia of peddling excuses.

"Let's be frank, we've had enough of hearing the same things for 20 years, imagine the seven million people who have stopped voting for the centre right," said Alfano.

"Forza Italia should recognise that mistakes have been made over the last 20 years and stop insulting us. We were the ones who most believed (in the project) and who suffered most for the mistakes". Alfano's remarks provoked outrage in FI. "I don't feel a useless idiot," Giovanni Toti, the former news chief of one of Berlusconi's TV channels who was appointed political advisor in FI last month, told State broadcaster Rai.

"If there are too many useless people, Alfano should look at himself. He has some responsibility as he was the secretary of (Berlusconi's now defunct) People of Freedom party.

"He says he doesn't recognise Berlusconi any more. I wonder whether Berlusconi recognised Alfano when he decided to stay in the government and split the party".