Right-wing populist Matteo Salvini has spoken out in favour of Theresa May.
It comes as she has been trying to gather support from the 27 EU members for her Brexit plan outlined in Chequers.
He said Italy “definitely” wanted the UK to walk away with a good deal.
The populist continued: “I hope the negotiations end well for the UK to serve as an example of the people coming out on top of the EU.
“I remember the referendum stage as an example of participation and freedom; I hope it can be an opportunity for the British.”
Theresa May has dispatched members of her cabinet across Europe to sell her Chequers deal.
Her attempt to bypass the EU Commission by dealing directly with European leaders has stalled with some siding with the bloc’s position.
But Mr Salvini seemed to support the Prime Minister and said Italy would be the UK’s friend in negotiations.
The populist also warned Theresa May she must take a tough stance with negotiations.
Speaking to the Sunday Times, he said: “My experience in the European parliament tells me you either impose yourself or they swindle you.”
The leader of the anti-immigrant Lega said the Prime Minister should be prepared to walk away without a deal.
He added: “Because on some principles there is no need to be flexible and you should not go backwards.”
Mr Salvini also accused the EU of trying to punish the UK for voting to leave the bloc.
He blasted: “There is no objectivity or good faith from the European side.”
Theresa May’s plan was dealt a blow when Michel Barnier rejected the customs proposals as “unworkable”.