The seven Republicans seeking their party's nomination to oppose U.S. President Barack Obama in next year's election participated in the first major debate of this campaign season Monday evening.

The Republican contenders criticized President Obama's handling of the economy at the event in Manchester, New Hampshire, and largely focused on how they would cut taxes and shrink the size of the government as a way to re-ignite economic growth.

The northeastern state of New Hampshire holds the first primary election early in 2012, nine months before the general election that will determine whether Mr. Obama, a Democrat, will remain in office for another four years.

At the debate was the presumed front-runner in the race for the Republican nomination — former Massachusetts governor Mitt Romney. However, many Republicans consider him too moderate in a party that has become increasingly conservative.

They point to passage in Massachusetts when he was governor of a state health care plan that served as a model for Mr. Obama's nation-wide health care reform law. Republicans at the debate called for the repeal of the Obama reforms.

One of the best known among the seven is former House speaker Newt Gingrich, whose race for the White House has been threatened by last week's mass resignation of his campaign staff.

Another well-known Republican politician is former Alaska governor Sarah Palin. But she has yet to declare her candidacy and did not participate in the debate.

The debate was nationally-televised on the news channel CNN.

Also joining in the debate were former Minnesota governor Tim Pawlenty and a congresswoman from the state, Michele Bachmann, a favorite of the anti-tax Tea Party movement.

During the debate, Bachmann officially announced that she is running for president and had filed the necessary papers.

Filling out the field of seven were Georgia businessman Herman Cain, U.S. Representative Ron Paul of Texas and former Pennsylvania Senator Rick Santorum