WASHINGTON — Congress appears on track to avert a government shutdown this weekend, even as President Barack Obama’s push to extend a payroll tax cut and jobless benefits for another year is encountering snags.

Those hiccups in finding spending cuts to pay for extending a 2 percentage point cut in Social Security payroll taxes and jobless benefits for millions have prompted Democratic leaders to suggest just a two-month, $40 billion extension of expiring tax breaks and jobless benefits might be needed.

But the first act in clearing away a pile of unfinished business for an unpopular Congress is for the GOP-controlled House to pass a massive, bipartisan, $1 trillion-plus spending measure funding 10 Cabinet departments and U.S. operations in Iraq and Afghanistan.

That vote is on track for this afternoon, but a stopgap bill could be needed to fund the government into next week.

Senate Majority Leader Harry Reid, D-Nev., told reporters Thursday night that he was still optimistic that bipartisan talks on yearlong extensions of the Social Security payroll tax cut and unemployment coverage would succeed. But as a “Plan B,” he said, they were working on a two-month extension as well, which would also prevent cuts in Medicare reimbursements for doctors during that period.

“We’re still working on the long-term” bill, Reid told reporters as he exited the Capitol after a day of talks over both the payroll tax and spending measures. As for the two-month version, he said, “We’ll only do that if what we’re working on doesn’t work out.”

Reid’s remarks put a slight damper on a day on which for the first time, Democratic and Republican leaders expressed optimism at prospects for swift compromise on their payroll tax standoff and a spending battle that had threatened to shutter federal agencies beginning at midnight today.

A deal on the $1 trillion-plus spending bill was reached after Republicans agreed to drop language that would have blocked President Barack Obama’s liberalized rules on people who visit and send money to relatives in Cuba. But a GOP provision will stay in the bill thwarting an Obama administration rule on energy efficiency standards that critics argued would make it hard for people to purchase inexpensive incandescent light bulbs.

A senior White House official said the administration supported the two-month plan.

Bargainers were considering the two-month extension of this year’s payroll tax cut and unemployment benefits bill because so far, they haven’t agreed how a yearlong extension would be paid for.

The two-month bill would cost $40 billion, according to the aide. It would be paid for from a list of around $120 billion in savings that bargainers are considering, including sales of the broadcast spectrum and raising fees that Fannie Mae and Freddie Mac charge to back mortgages, the aide said.

Without congressional action, the payroll taxes would rise and extra benefits for the long-term unemployed would expire on Jan. 1. Doctors’ Medicare payments would be automatically reduced that day by 27 percent, a reduction that could prompt some to stop seeing Medicare patients.