President Trump’s last-minute move to reject a sweeping coronavirus relief package is escalating confusion and panic among Republicans while setting the stage for an uncomfortable confrontation Thursday that could lead GOP lawmakers to object to their own president’s demand for larger stimulus checks for Americans.

The chaos is unfolding against the backdrop of another threatened government shutdown, with funding set to lapse starting Tuesday unless a spending bill to keep federal operations running is signed into law along with the virus aid bill. While the president hasn’t explicitly threatened a veto, his defiance of a deal negotiated by his own administration could spark a standoff that could conceivably last until Joe Biden is inaugurated Jan. 20.

The continued mayhem Wednesday threw into doubt how quickly help would get in the hands of millions of Americans struggling under the economic weight of the pandemic, including the direct payments that had become one of the most visible provisions of the relief package. In a video that caught lawmakers by surprise, Trump decried some items as too costly while advocating larger, $2,000 stimulus checks for individuals rather than the current $600 level.

The fight also handed Democrats in two vital Senate races in Georgia a fresh political weapon against their GOP opponents, with Trump undercutting Republican Sens. David Perdue and Kelly Loeffler as they took a victory lap over securing the $600 checks.

House Speaker Nancy Pelosi (D-Calif.) announced Wednesday that Democrats would seek to pass a bill at a short Thursday House session that would provide $2,000 checks, though the measure could easily be blocked by Republicans, as it would require unanimous consent from House members.

“As I’ve said from the start, the Senate should have acted on this months ago and support for Georgians should have been far greater,” said Democrat Raphael Warnock, who is challenging Loeffler in Georgia. “Donald Trump is right: Congress should swiftly increase direct payments to $2,000. Once and for all, Sen. Loeffler should do what’s best for Georgia instead of focusing on what she can do for herself.”

At the same time, Trump is facing pressure from the right to veto the massive package for reasons of cost. Russell Vought, the director of the Office of Management and Budget, wants the president to veto the measure, adding to a drumbeat from conservative radio hosts and advocacy groups.

“The process was the worst I’ve ever seen, on any bill in Congress, and we’re already looking at a $1.8 trillion annual deficit — and that’s before this,” said Jason Pye, vice president of legislative affairs for the conservative organization FreedomWorks.

Trump could veto the coronavirus relief and spending bill by doing nothing — the bill has yet to be transmitted to Trump, meaning the 10-day veto window will expire after the current Congress adjourns on Jan. 3. Unemployment insurance benefits are also set to expire for 12 million Americans on Saturday.

But multiple congressional aides said their real deadline of concern was Monday at midnight, when a temporary government funding bill expires.

If the standoff is not resolved by then, the aides said, an extended government shutdown could potentially continue until Biden’s inauguration. While Democrats are happy to increase the size of the stimulus checks, they said, they will not be willing to pursue a wholesale renegotiation of the relief bill or the $1.4 trillion spending bill for fiscal 2021, which were negotiated separately and then joined for passage.

Democratic leaders on Wednesday discussed passing another temporary funding measure when they reconvene Monday, but it was unclear how long it would run, whether the Senate would quickly pass it or if Trump would sign it.

Instead, they are likely to simply insist Trump sign the bill that was already passed.

The feuding over the fate of direly needed virus aid is just one chapter of a broader war that a furious Trump has waged against Congress and even members of his own party since losing to Biden in the Nov. 3 election. Trump vetoed a popular defense policy bill earlier Wednesday and continued to rage against lawmakers who weren’t joining his efforts to overturn the outcome of the election.

As Trump left Washington on Wednesday to spend the holidays in Palm Beach, Fla., White House aides were receiving an avalanche of angry messages from GOP lawmakers and consultants, who said they felt abandoned by Trump after administration officials said he supported the bill and asked them to vote for it.

Many of the concerns focused on what the fallout could be for the Senate races in Georgia, said two people with knowledge of the messages, who like others requested anonymity to discuss internal communications. For the president’s part, he has been complaining to advisers that GOP lawmakers such as Senate Majority Leader Mitch McConnell (R-Ky.) are not doing enough to help him in his bid to overturn his election loss.

On the spending legislation, Trump is displeased with Treasury Secretary Steven Mnuchin, his chief emissary to congressional leaders, and does not even want to speak to him about the issue, according to a senior administration official. Mnuchin — who first came up with the $600 figure for the checks — called GOP lawmakers in recent days and asked them to support the bill because the president supported it.

Among those blindsided were McConnell and House Minority Leader Kevin McCarthy (R-Calif.), who were not told in advance of the Tuesday night video in which Trump outlined his complaints over the package, and they called staffers to ask what was going on, according to three people familiar with the matter.

On a conference call with House GOP lawmakers Wednesday afternoon, McCarthy said Trump is undecided on a veto and urged them to support the changes he wanted, according to three Republicans with knowledge of the conversation. McCarthy also said Republicans are exploring options for offering a unanimous consent request of their own that Democrats would have to oppose.

McConnell — who has been on the outs with Trump since publicly acknowledging Biden as the president-elect — does not plan to speak to Trump about it, with one adviser to the majority leader saying he “does not think it would be helpful.”

Legislative affairs staffers and others involved in the negotiations had no idea Trump was taping the video and apologized to the surprised lawmakers, officials said. He taped it around noon on Tuesday, even as other staffers continued to tell reporters and lawmakers that Trump was going to sign the bill.

The script decrying the bill was not written by people involved in the negotiations, and some aides have been trying to decipher where it came from. Several aides hoped Trump would still sign the bill, noting he did not explicitly say he would veto it.

“Only Trump could take a final big win for his administration and in a fit of illogical madness disown any credit he’ll ever get for it,” said one senior GOP official. “To the extent that Trump’s bizarre ramblings contribute to any negative feelings for Republicans, Perdue and Loeffler are the ones who will ultimately pay the price.”

During his time in office, Trump has regularly had outbursts over legislation that advisers previously signaled he would endorse, prompting scrambles to coax him into ultimately signing a bill. But in the last throes of his presidency, many of the guardrails around Trump have been removed through departures — leaving the tempestuous president to his own devices.

White House staff secretary Derek Lyons would usually coordinate the process for a video like the one that upended the relief package by circulating scripts for approval. But Lyons’s last day was Friday, and White House Chief of Staff Mark Meadows told staff not to circulate the script for the relief bill video, according to aides.

As for Meadows himself, he is not in Washington and left town before Trump posted the video on Twitter. The chief of staff, who told aides to keep the video closely held, had been one of the main forces within the administration arguing against the $2,000 stimulus checks that the president is now pushing, making the case that enlarging the payments could blow up the entire negotiations, according to people familiar with the issue.

Others close to Trump — his presidential campaign manager, Bill Stepien; Republican National Committee Chairwoman Ronna McDaniel; and senior adviser and son-in-law Jared Kushner — are also missing in action.

In addition to playing up the issue in Georgia, congressional Democrats are seeking to capitalize on the chasm between Trump and virtually the rest of the Republican Party on direct payments in other ways.

In a brief conference call Wednesday evening, Pelosi told House Democrats that they would seek to pass a bill raising the checks from $600 to $2,000. If Republicans object, more action could be taken on Monday, when the House is scheduled to reconvene.

She said the pressure fell on McCarthy and McConnell to talk to Trump and break the impasse. “It’s on them,” she said.

The bill, written by House Ways and Means Committee Chairman Richard E. Neal (D-Mass.) itself modifies a section of law created by the larger bill, so it only takes effect if Trump signs both.

What remained unclear Wednesday was whether Democrats would force a confrontation on the House floor, prompting a Republican to publicly object on camera to bigger checks.

Under long-standing House practice, such live unanimous consent requests are not in order unless they have been pre-cleared by each party's leadership. But that policy is established at the speaker's discretion, and Pelosi could change it to allow for a televised spectacle Thursday morning.

If the unanimous consent gambit fails Thursday, House Democrats are discussing moving to hold a vote on it Monday when members are scheduled to be in Washington for a vote on overriding Trump's Pentagon bill veto, according to two Democratic aides who described the discussions.

Underscoring the bizarre circumstances, Pelosi’s letter to Democratic lawmakers began with the words: “Just when you think you have seen it all.”

“The entire country knows that it is urgent for the President to sign this bill,” Pelosi wrote, “both to provide the coronavirus relief and to keep government open.”

Jeff Stein contributed to this report.