LOS ANGELES — Texas governor Rick Perry squared up to make his debut Wednesday at a Republican party debate, after surging into the race as frontrunner to be the GOP candidate against Barack Obama next year.

The main Republican contenders for the US presidency are to take the stage at the Ronald Reagan presidential library in California Presidential Library in Simi Valley, California, for the two-hour debate from 5:00 pm (0000 GMT).

Jobs and the struggling US economy are likely to feature high on the debate's agenda, ahead of a keynote speech by President Obama Thursday aimed at tackling zero US job growth and reviving his own political fortunes.

Perry joined the Republican field for the White House in the last month, energizing a lackluster GOP race and leapfrogging straight into the lead ahead of former Massachusetts governor Mitt Romney.

A poll last week by the Quinnipiac University put Perry on 24 percent among Republican and independent voters, followed by Romney -- who set out a 59-point economic plan in Las Vegas on Tuesday -- with 18 percent.

But with no single candidate inspiring voters there is everything to play for at Wednesday's debate, where up-and-coming Tea Party favorite Michele Bachmann will also be seeking to capitalize on the movement's popular appeal.

Bachmann, of Minnesota, will be trying to grab back the spotlight seized by Perry when he announced his candidacy in mid-August, taking media attention away from her victory in a GOP presidential straw poll in Iowa, CNN said.

Also on stage will be former House Speaker Newt Gingrich, Ron Paul of Texas, businessman and former talk show host Herman Cain, former senator Rick Santorum of Pennsylvania, and former Utah governor and US envoy to China Jon Huntsman.

As well as the struggling economy -- seen as a key area of vulnerability for Obama -- the debate could see the candidates stake out positions on Tea Party hot button issues including global warming, abortion and the threat of China.

While much can happen as hopefuls jostle for position ahead of the party primaries, for the moment Perry and Romney appear the frontrunners to take on Obama in the November, 2012 presidential election.

Not among the Republican candidates -- yet -- is former Alaska governor and surprise 2008 vice-presidential nominee Sarah Palin, who has kept observers guessing about whether she throw her hat into the White House ring.

Former New York mayor Rudy Giuliani also raised eyebrows this week when he said he might even consider running for the GOP nomination.

The tough-talking Giuliani -- widely praised for his handling of the September 11, 2011 attacks -- told reporters on the eve of the 10th anniversary of 9/11 that: "If I think we are truly desperate, then I may run."

Without commenting on the perceived lack of a real GOP heavyweight candidate, he noted that this was how he was elected mayor of New York City. "You know what my slogan was? 'You can't do any worse'," he joked.

The GOP debate -- held at the Reagan presidential library in the picturesque Simi Valley north of Los Angeles -- is the first of three over the next two weeks.

Cable news channel CNN is to host a "Tea Party Republican Debate" on September 12, followed by a Fox News-organized event on September 22, both in Florida.