Washington - After more than a year on the campaign trail, Senator Hillary Clinton returned to her day job on Tuesday in the US Senate to the sound of hearty applause and cheers, media reports said.

Clinton stepped down from her bid for the Democratic presidential nomination earlier this month, after losing the battle for delegates against Senator Barack Obama, who has become the presumptive nominee of the centre-left party.

She has pledged to now turn her energy toward getting Obama elected president on November 4.

The two politicians are to meet Thursday night to discuss campaign finance, including the possibility that Obama could take over some of Clinton's 30 million-dollar-campaign debt and receive her valued list of financial backers in exchange, CNN reported.

On Friday, Clinton and Obama are to appear together for the first time on the campaign trail - symbolically, in the New Hampshire town of Unity, where they each received 107 delegate votes in the January primary vote.

Speculation continues about whether Obama will name Clinton as his vice presidential candidate - a role she has declared she would accept.

But Obama has remained silent on the subject.

On Tuesday, Obama said in broadcast remarks that Clinton would be "a force to be reckoned with not only in the Senate abut also, if I'm successful in the White House, she's going to be one of my key partners."

In the polls, Obama outpaces Republican contender John McCain by a 48 to 40 per cent margin, according to Realclearpolitics. com, which calculates averages of polls.

The Los Angeles Times/Bloomberg poll Tuesday reported Obama with a 12 per cent lead over McCain. The poll's margin of sampling error was plus or minus 3 percentage points. (dpa)