Mitt Romney accuses John McCain of 'dirty tricks'

California: Republican presidential candidate Mitt Romney has accused his rival John McCain on Wednesday resorting to "dirty tricks" for saying he had backed a timetable for withdrawing US troops from Iraq.

Simmering tensions from the campaign for Florida, where McCain outshone Romney to win the Republican nomination contest on Tuesday spilled over into a crucial debate in California.

Romney, a former Massachusetts governor fighting to win more votes in "Super Tuesday" next week, accused McCain of lying about his Iraq record.

Those races could determine the Republican Party's choice for the November 4 election against a Democratic candidate to succeed President George W. Bush.

Gone from the debate at the Ronald Reagan Presidential Library was Former New York Mayor Rudy Giuliani, who pulled out of the race after a dismal finish of the Florida leg.

Romney's job was to try to stop the momentum of McCain, who leads opinion polls in some of the key "Super Tuesday" prizes California, New York and New Jersey.

Romney accused McCain of holding liberal positions out of step with mainstream Republicans.

In response, McCain said Romney raised taxes as governor of Massachusetts and suggested he had changed his position on important issues.