Lawmakers are returning to Capitol Hill to wrap up work on the budget, highway funding and taxes, an end-of-the-year stretch that will test the standing of Republican leaders like House Speaker Paul Ryan with the GOP's tea party wing and its anti-establishment presidential candidates.

There are less than two weeks until a deadline to pass a $1.1 trillion catchall spending bill to fund Cabinet agencies and avoid a holiday season government shutdown. If the process doesn't go smoothly, a last-minute temporary funding measure would be required to keep the government open when the current stopgap funding measure expires Dec. 11.

The so-called omnibus spending bill represents a challenge for Ryan, R-Wis., who took over the top House job after former Speaker John Boehner, R-Ohio, was forced out this fall over his penchant for looking to Democrats to pass major legislation like year-end spending bills, among other reasons.

Ryan is sure to have to do the same this time around despite pressure from outside groups like the Heritage Foundation to force battles over trying to use the must-do measure to take away federal funding from Planned Parenthood or deal with worries about Syrian refugees in the wake of the Paris attacks.

But the renegades that ran Boehner out of Washington aren't in any mood to rough up Ryan just yet.

"I think it's unfair to hold Paul Ryan accountable for this particular omnibus. The Dec. 11 crisis that our leadership created is one of the reasons we got rid of our leadership," said Rep. Thomas Massie, R-Ky., a tea party favorite. "It's not of his making, and I personally would not write him off if something doesn't happen on this omnibus, whether it's Planned Parenthood ... or something else."

Sen. Ted Cruz, R-Texas, who is rising in the national presidential horserace polls, is another matter altogether. If past is prologue, he's sure to use debate on the omnibus measure to burnish his reputation for attacking Capitol Hill GOP leaders and build opposition to the catchall spending compromise among Republican voters.

House-Senate negotiations on a long-term measure funding highway and transit programs seem likely to finally produce results, helped in large part by a new "offset" to help pay for the measure that involves a money shuffle from the Federal Reserve to the Treasury. At issue is a House provision to eliminate $29.3 billion in the Federal Reserve's capital surplus account and prevent the Fed from depositing future profits there.

Budget watchdogs call the money transfer a complete gimmick and say that the additional highway spending it is being used to justify will increase the federal debt by at least $59 billion over the coming 10 years. But free money is a precious commodity in Washington and given the popularity of highway spending -- as well as the sweeping 354-72 House vote for the move -- the common wisdom is that the dubious offset will stay.

Another item on the must-do list involves extending already expired tax breaks in time for the upcoming filing season.
Businesses big and small would continue to claim dozens of tax breaks that expired at the start of the year under a bill that overwhelmingly passed the Senate Finance Committee.

Struggling homeowners and people who live in states without a state income tax would get to keep their tax breaks, too. The $95 billion package would extend more than 50 tax credits, exemptions and deductions through 2016. Support for these so-called tax extenders is bipartisan.

Among the biggest breaks for businesses are a tax credit for research and development; an exemption that allows financial companies such as banks and investment firms to shield foreign profits from being taxed by the U.S.; and several provisions that allow businesses to write off capital investments more quickly.

There is also a generous tax credit for using wind farms and other renewable energy sources to produce electricity.

More narrow provisions include tax breaks for filmmakers, theatrical productions, racehorse owners and NASCAR track owners. The biggest tax break for individuals allows people who live in states without an income tax to deduct state and local sales taxes on their federal returns.

Before turning to the must-do business, GOP leaders are devoting the House and Senate floors to taking on President Barack Obama's health care law and his climate change agenda.

The Senate is turning to a rare opportunity to employ fast-track procedures to pass a bill to repeal much of the Affordable Care Act and "defund" Planned Parenthood. The fast-track legislative process would remove the threat of a filibuster by Democrats. The measure would have to be reconciled with a House-passed version before it can be shipped to Obama, however.

Meanwhile, with Obama in Paris for a U.N. conference on global warming, House GOP leaders have slated votes to disapprove two recent administration regulations on greenhouse gas emissions from power plants. The move would send the measures to Obama's desk, and he is sure to veto them.