Congress is poised this week to dive into an epic combat over spending, because the Senate for the primary time in years places appropriations payments on the ground for debate and Speaker Kevin McCarthy tries to seek out his means out of a posh funding tangle that would in the end threaten his management put up.

With lower than three weeks remaining earlier than authorities funding runs out on Sept. 30, Congress has not cleared any of its 12 annual appropriations payments, although there was extra progress than within the latest previous. Given the quickly approaching deadline, leaders of each the House and the Senate agree {that a} short-term stopgap funding measure might be wanted to avert a authorities shutdown starting Oct. 1. But that normally routine laws is dealing with main obstacles within the Republican-led House, making its path to President Biden’s desk unusually fraught.

Members of the House’s far-right Freedom Caucus are pledging to oppose even a brief measure if it doesn’t reduce funding considerably or embrace new border controls and restrictions on prosecuting former President Donald J. Trump. At the identical time, senators of each events need the stopgap invoice to incorporate billions of {dollars} in new help to Ukraine, a requirement that House Republicans are resisting. House Democrats need nothing to do with any of the Republican payments, which have additionally been loaded with conservative social policy riders which have little probability of enactment.

“Honestly, it’s a pretty big mess,” Senator Mitch McConnell, Republican of Kentucky and the minority chief, just lately advised an viewers in his house state.

The main impediment for Mr. McCarthy is {that a} vital section of the hard-right members in his ranks are insisting on circumstances on the short-term funding measure that would by no means clear the Democratic-led Senate at the same time as they name for deeper spending cuts within the full-year spending measures that a lot of their fellow House Republicans won’t help. That inner divide and variations over abortion coverage and different points forced Mr. McCarthy to pull funding measures from the floor simply earlier than the August recess.

With solely 4 G.O.P. votes to spare, Mr. McCarthy can afford few defections if he hopes to cross spending payments with solely Republican help, and the archconservatives are digging in whereas dismissing the political and financial repercussions of a authorities shutdown. They have additionally rejected Mr. McCarthy’s argument {that a} shutdown would stall Republican investigations and a possible impeachment of Mr. Biden.

Representative Chip Roy, an ultraconservative Republican from Texas, warned final week on X, previously Twitter, that “hiding behind impeachment to screw America with status quo massive funding” would “not end well.” He additionally ridiculed “hand-wringing” over the potential penalties of a shutdown and urged Republicans to organize for a showdown after they returned to Capitol Hill.

“Saddle up,” Mr. Roy wrote.

An added complication for Mr. McCarthy is {that a} stopgap measure would maintain the federal government funded at a degree set in December 2022, when Democrats nonetheless managed each the House and the Senate. Only a handful of House Republicans voted for the cash in that vast catchall spending measure, and most of them have since left Congress.

“We are talking about continuing-resolution levels that almost all of us just voted against,” mentioned Representative Ken Buck, Republican of Colorado, predicting that many Republicans would balk at backing a stopgap measure if the funding remained regular. “I honestly think McCarthy will need to get it done with Democratic votes, and there will be other consequences for that.”

Should Mr. McCarthy be compelled to show to Democrats to cross the stopgap measure or different funding payments, as he did in May to avert a federal default by suspending the debt restrict, some Republicans are already threatening to problem his management place by calling on the House to vacate the speaker’s chair.

“I think that everything is on the table to hold the speaker accountable,” Representative Bob Good, Republican of Virginia, mentioned final week in an interview on Fox Business Network. He mentioned Mr. McCarthy would want to selected between slicing a take care of Democrats or returning authorities spending to prepandemic ranges.

One potential benefit for Mr. McCarthy is that the Biden administration has requested $16 billion in emergency catastrophe funding for restoration from storms, floods and wildfires in Florida, Hawaii, Vermont and elsewhere. A reluctance to oppose catastrophe help can generally elicit votes from in any other case recalcitrant lawmakers.

The funding dynamic is totally completely different within the Senate, the place Republicans and Democrats on the Appropriations Committee have been working cooperatively to advance spending payments at a better degree than what’s being thought of within the House. Leaders of the panel have additionally saved the payments freed from the contentious coverage riders which are drawing hearth within the House.

The Senate this week is scheduled to think about measures funding veterans, agriculture and housing applications — the primary time in years that spending payments have been thought of individually on the ground because the chamber strayed removed from the normal appropriations course of. Votes on proposals to vary the laws are anticipated, however Senate leaders hope to win fast approval, offering leverage over the House ought to Mr. McCarthy be unable to push any spending payments over the end line. The House is planning this week to take up only one spending invoice protecting the Pentagon.

“We have provided a clear bipartisan road map to fund the government under extremely difficult constraints, proving Congress can work together and through its differences,” mentioned Senator Patty Murray, Democrat of Washington and the chairwoman of the Appropriations Committee.

Yet the variations between the Senate and the House are vital, and House conservatives have made it clear that they regard their push to considerably rein in spending as much more consequential than the repercussions of letting funding for federal companies run out.

“If a temporary shutdown is more concerning to you than our $2 trillion deficit and $33 trillion national debt, I’d politely suggest you’re part of the problem,” Representative Ralph Norman, Republican of South Carolina, wrote on X final week.

But Democrats stand able to level the finger at House Republicans if authorities companies are shuttered, and Mr. McCarthy is painfully conscious that his occasion can be blamed for a shutdown.

“A shutdown is unnecessary and would harm many American families and businesses — just about everybody,” mentioned Senator Chuck Schumer, Democrat of New York and the bulk chief. “We hope the House comes to its senses and follows our example.”