Mitt Romney, the former Governor of Massachusetts who abandoned his run for the White House earlier this month, has endorsed Senator John McCain.

On Super Tuesday, when almost half of the states chose a Republican candidate, he was roundly defeated by Senator McCain and lost a string of Southern states to Mike Huckabee, the former Governor of Arkansas.

Romney had accumulated an estimated 285 delegates by the time he suspended his campaign.

He has asked them to support the Arizona Senator.

“Even when the contest was close and our disagreements were debated, the calibre of the man was apparent,” Governor Romney said yesterday at a press conference with Senator McCain.

“As a party, we come together.”

Romney, who spent tens of millions of dollars of his own money on his bid for the White House, took seven states on Super Tuesday: Massachusetts, where he was Governor from 2003 to 2007, Alaska, Utah, North Dakota, Minnesota, Montana and Colorado

Earlier in the election cycle he won Wyoming, Michigan, Nevada and Maine.

However, he was weakened by defeat in Iowa at the hands of Huckabee and in New Hampshire at the hands of McCain.

Arizona Senator John McCain is now almost certain to become the Republican candidate for President, but it could be a tough battle for him to win over sections of his own party.

Mr Huckabee, a charismatic former Baptist minister, has vowed to stay in the race as the only candidate the Christian Right have left.