By John Whitesides
MANCHESTER, New Hampshire (Reuters) - Seven Republican presidential contenders meet face-to-face in their first major debate on Monday as the fight for the party's 2012 nomination enters a new phase.
The nationally televised forum in New Hampshire will include most of the top-tier contenders in the Republican battle for the right to challenge President Barack Obama, including Mitt Romney and Michelle Bachmann.
Romney, Bachmann and Newt Gingrich skipped a lightly attended debate last month, but will appear on Monday with four contenders who participated in the first one -- former Senator Rick Santorum, former Minnesota Governor Tim Pawlenty, former pizza executive Herman Cain and U.S. Representative Ron Paul.
"This marks the start of a new phase for the campaign as more people pay attention and the candidates begin to engage," said Fergus Cullen, a former chairman of the New Hampshire Republican Party.
The debate on the campus of Saint Anselm College in New Hampshire will begin at 8 p.m. EDT and be aired on CNN.
Romney, the former governor of Massachusetts, leads the Republican pack in most polls but is an uneasy front-runner in a group that has drawn complaints from some in the party for being a weak field.
Obama heads most polls against the Republican hopefuls, despite high unemployment.
The biggest competition at the debate could be among candidates vying to become the prime alternative to Romney.
"Now is the chance for them to start to distinguish themselves," said Dante Scala, a political scientist at the University of New Hampshire.
HUNTSMAN SKIPS DEBATE
Bachmann could be a natural for the role. Her fiery attacks on Obama, Washington insiders and even her own party's leaders have made her a hit with cable news and conservative Tea Party activists.
She clearly stands out as the only woman in the field, but many Republicans have questioned whether she can form a credible national campaign.
Gingrich, a former speaker of the House of Representatives, also faces skepticism about his future after staff desertions and a disastrous campaign launch that included an apology for criticizing Republican Representative Paul Ryan's budget plan.
Bachmann and former U.S. Ambassador to China Jon Huntsman are expected to formally declare their candidacies soon, although Huntsman's decision to skip the debate puzzled some in the state.
New Hampshire holds the second nominating contest and could play a crucial role in the 2012 Republican nominating fight, and the debate will give candidates a high-profile chance to make a direct appeal to state activists.
Other Republicans are still considering entering the race at the urging of party members dissatisfied with the current field. Sarah Palin, the 2008 vice presidential nominee, and Texas Governor Rick Perry are among those considering a run.
"The first debate felt like a junior varsity game. This one is still missing a few players, but it feels like the varsity," said Dan Schnur, an aide on Republican John McCain's 2000 presidential run who is now at the University of Southern California.
(Editing by Eric Beech)