U.S. lawmakers face a lengthy to-do list, topped by a dispute over expiring tax cuts, when they return to work on Monday in a session that offers an early gauge of the chances for bipartisanship when the new Congress convenes in January.

The first test of the post-election relationship between President Barack Obama and newly powerful Republican congressional leaders will come at a White House meeting on Tuesday, which is likely to focus on the tax-cut debate.

Republicans have demanded all the Bush-era tax cuts, which expire at the end of the year, be permanently extended. Obama and many Democrats want to make the cuts for families making less than $250,000 a year permanent, but would let taxes increase for wealthier Americans.

The tax clash promises to be an early test for Obama and Republicans, who take control of the House of Representatives in January after gaining 63 seats in November's elections. Republicans also gained strength in the Senate, where Democrats will retain a majority in the new Congress.

Some Democrats have floated various compromises on taxes, including temporary extensions or raising the high-earner threshold to $1 million. Other Democrats have urged Obama to stand strong against extending the tax cuts for the wealthy, citing the cost of $700 billion over 10 years.

"What's likely to happen is there will be an extension of the tax cuts for everybody for a period of time. I don't know what that might be, but it's the wrong remedy for the country," Democratic Senator Byron Dorgan told CNN's "State of the Union."

Republican Senator Lindsey Graham also predicted the tax cuts would be extended temporarily.
"There will be bipartisan support ... to extend all the tax cuts for two or three years, and I think that vote will be had before the end of the year," he said on Fox News Sunday.

The jammed legislative agenda for the session also includes ratification of the START nuclear treaty with Russia, repeal of the "don't ask, don't tell" policy banning gays from the military, an extension of long-term unemployment benefits and a spending bill to keep the government running.

Lawmakers, who took last week off for the Thanksgiving holiday, will have just four work weeks before the Christmas holiday and the end of the old Congress to finish their work. New members of the House and Senate take office in January.

"My issue is you can't do everything. I was stating it as a matter of reality, not a matter of policy," Republican Senator Jon Kyl said on NBC's "Meet the Press" when asked about his opposition to taking up the new START treaty with Russia.

Kyl said there was no time for Senate Democratic leader Harry Reid and the Senate to consider the treaty, which would cut the two countries' deployed nuclear weapons by about 30% within seven years.

"How can Harry Reid do all the things we're talking about, deal with expiring tax provisions and in addition to that dealing with the START treaty, which by itself could last two weeks?" Kyl asked.

Congress must also approve a spending bill to keep the government running, and is expected to debate a repeal of the "don't ask, don't tell" policy that bans gays from openly serving in the military.

Graham said there was no chance a repeal would pass the Senate. "Don't ask, don't tell is not going anywhere," he said on Fox New Sunday.