Umberto Bossi, a key ally of Italian Prime Minister Silvio Berlusconi and known for his caustic remarks, sparked controversy yesterday after insulting Rome by calling its inhabitants “pigs”.

“I have had enough with ‘Senatus Populusque Romanus’,” he said in a speech on Sunday referring to the city’s motto meaning “The Senate and the Roman People”. The Rome motto still appears, as SPQR, on the city’s coat of arms and the letters are inscribed on Rome’s buildings, manholes and public archives.

“I say: These Romans are pigs,” Mr Bossi declared.

Mr Bossi, leader of the Northern League party which supports autonomy for northern Italy and is Mr Berlusconi’s chief coalition partner, also said that he opposed moving the Formula 1 Grand Prix from the northern town of Monza to Rome.

“Romans can always run – hands off Monza and in Rome they can do the chariot race,” he said, alluding to one of the favourite sports in ancient Rome.

The insult was met with laughter from the audience, including Mr Bossi’s son Renzo who also provoked controversy when he stated that he would not support the Italian football team during the 2010 World Cup in South Africa.

Rome mayor Gianni Alemanno, a member of Mr Berlusconi’s party, said this time Bossi “has really gone too far, not only by insulting current-day Rome but also the city of the past.”