An Italian minister from an anti-immigrant party who wore a T-shirt that offended Muslims in 2006 said yesterday the gesture was misunderstood and his appointment should not damage relations with Libya.

Roberto Calderoli of the Northern League was appointed this week to the new government of Silvio Berlusconi, who was installed as Prime Minister for a third term.

Mr Berlusconi faced a diplomatic clash with Libya - and possible energy sanctions - after Tripoli made it clear it objected to Mr Calderoli's appointment. He quit Mr Berlusconi's last government in 2006 after wearing a T-shirt showing a Danish cartoon of the Prophet Mohammed that angered Muslims worldwide. He was blamed for rioting that broke out at the Italian consulate in the Libyan city of Benghazi. Returning as minister for "simplification" - a new post without a full ministerial portfolio - Mr Calderoli was asked by Italian television about Libya's angry response to his appointment, and whether he regretted the T-shirt incident.

He said he was sorry for the consequences of his act which he said was misinterpreted as anti-Islamic provocation.

"Mine was a message of peac and rapprochement between the monotheistic religions but was misunderstood," he said. "I hope there aren't any problems today linked to something in the past that should be considered water under the bridge."

Since the T-shirt incident, Mr Calderoli has continued to offend Muslims in Italy by protesting at the construction of new mosques and threatening "pig day" protests to defile them. He once walked his own pet pig over a site intended for a mosque.

Libya warned of "catastrophic consequences" if he was appointed and reacted to his swearing-in on Thursday by saying it would no longer cooperate with Italy on preventing illegal immigrants from Africa landing on Italian shores.