U.S. presidential hopeful Mitt Romney holds a commanding lead on the eve of the Florida Republican primary, which could be a pivotal contest in the race for the party nomination.

A Quinnipiac University Polling Institute survey of likely Florida voters indicates Romney has a 43- to 29-percent lead on his closest rival, former House speaker Newt Gingrich.

Both candidates are campaigning hard in the southeastern state, before the primary that could have a huge impact on the battle to face Democrat Barack Obama in the November presidential election.

Romney, a multi-millionaire investor and former governor of Massachusetts, has courted voters alongside Senator John McCain, a rival in the presidential nominating contest four years ago.

Gingrich lashed out at Romney on Monday, accusing him of being a liberal and running dishonest political ads. The former House speaker says he expects a long campaign in the battle for the Republican presidential nomination.

Romney needs a win in Florida to regain his momentum after losing to Gingrich in the South Carolina primary January 21. After a week of fierce campaigning, polls show Romney's lead widening.

Speaking after a church service Sunday near the city of Tampa, Gingrich called Romney a “pro-abortion, pro-gun control, pro-tax increase moderate from Massachusetts.”

Romney has previously said that Gingrich is making excuses for his debate performances, and blasted Gingrich for being found guilty of ethics violations that forced him to resign as House speaker.