The once-promising relationship between House Speaker Nancy Pelosi and Treasury Secretary Steven Mnuchin flamed out publicly Thursday just days before the election, as the two disavowed economic relief talks -- and each other. `

It started before dawn when Pelosi (D-Calif.) dispatched a letter to Mnuchin detailing multiple outstanding issues in their on-again, off-again talks around a $2 trillion stimulus bill. Mnuchin was offended that the first he saw of the letter was in the media, when Politico’s morning newsletter Playbook published it shortly after 6 a.m. -- although Pelosi aides said they’d sent it to the Treasury secretary shortly after midnight.

By late afternoon, Mnuchin was responding in kind, tweeting out a letter to Pelosi that began dramatically, “Dear Speaker Pelosi: I woke up this morning and read your letter to me in the press. Because you sent it to my office at midnight and simultaneously released it to the press, I can unfortunately only conclude it is a political stunt.”

In keeping with their new frosty rapport, Mnuchin tweeted the letter out just one minute after sending it to Pelosi’s office. In the letter, he noted that he and Pelosi had spoken almost daily for the past 45 days “in an attempt to reach a serious bipartisan compromise,” amid a spiking pandemic and worsening economic conditions.

Indeed the fact that Mnuchin and Pelosi had continued negotiating as long as they did had mystified much of Washington. Senate Majority Leader Mitch McConnell (R-Ky.) had ruled out a pre-election vote on an enormous new spending bill weeks ago, seemingly foreclosing any path to an outcome.

But Pelosi and Mnuchin kept at it, with lengthy phone calls, offers and counter-offers. Their in-person meetings stopped after President Trump contracted the coronavirus earlier this month, although Mnuchin never tested positive. Pelosi and Mnuchin were able to broker four laws earlier this year that directed $3 trillion in stimulus at the start of the pandemic. The final gaps, though, proved insurmountable and created a level of bitterness, according to their letters.

“Your ALL OR NONE approach is hurting hard-working Americans who need help NOW,” Mnuchin wrote in the last line of his two-page letter to Pelosi.

Pelosi’s office didn’t seem swayed.

“It is disappointing that the White House wasted time on this letter instead of meaningful responses to meet the needs of the American people,” Pelosi spokesman Drew Hammill said.

By all accounts, Pelosi and Mnuchin had worked well together and appeared reluctant to stop talking. Even with all hope for an outcome seemingly gone, Pelosi was still pronouncing herself optimistic in recent days. Their continued negotiations infuriated some Senate Republicans, who complained that Mnuchin was caving to Democrats’ demands.

That stopped Thursday, when her letter to Mnuchin laid out the many areas that remained unresolved in their talks, including state and local aid, school funding, child-care money, tax credits for working families, unemployment insurance aid and liability protections for businesses sought by the administration but opposed by Democrats

She also said she was still awaiting a final answer from the administration on agreeing to the Democrats’ language on a national coronavirus testing strategy — something Mnuchin had said Oct. 15 that he was prepared to accept subject to minor edits. Pelosi put the onus on Mnuchin, Trump and McConnell for a deal to emerge in the lame duck session — if at all.

“Your responses are critical for our negotiations to continue,” Pelosi wrote in her letter. “The President’s words that ‘after the election, we will get the best stimulus package you have ever seen’ only have meaning if he can get Mitch McConnell to take his hand off the pause button and get Senate Republican Chairmen moving toward agreement with their House counterparts.”

The only question that remained was whether the breakup between Mnuchin and Pelosi would be final -- or whether the two could come together and produce a relief bill during Congress’ lameduck session after the election.

Both Pelosi and Trump said Thursday they hoped to do that -- although they differed on what could or should happen.

Addressing reporters at her weekly news conference Thursday, Pelosi expressed optimism that former Vice President Joe Biden will win the election five days from now, and suggested she wanted to clear the decks for him. But Pelosi also said she would not accept a small bill with the idea of coming back for more once a Biden administration begins.

House Speaker Nancy Pelosi (D-Calif.) on Oct. 29 said she believes Democratic presidential nominee Joe Biden will be elected president on Nov. 3. (The Washington Post)

“We’re not talking size, we’re talking quality. We’re not going to take a small bill” that still has provisions Democrats deem unacceptable, Pelosi said.

“I want a bill for two reasons. First and foremost the American people need help. They need real help. And second of all, we have plenty of work to do in a Joe Biden administration ... So we want to have as clean a slate as possible going into January,” Pelosi said.

Trump, meanwhile, told reality television host Jon Taffer in a podcast released Thursday that the administration would reach a stimulus deal after the election and predicted Republicans will retake the House -- a prospect political analysts on both sides view as exceedingly unlikely.

“Once we get past the election, we’re going to get it. It may be bipartisan, it may not have to be. Depending on -- if we win the House, it won’t have to be. Right after the election, we’ll get it one way or the other,” Trump said.

Trump added of extending the small-business Paycheck Protection Program: “No matter who you are; no matter how cold; how mean; how nasty – and you have some beauties in Washington – it makes sense.”

Pelosi’s letter did not reveal any new outstanding issue that had not already been publicly known. But it summed it all up, casting everything in a newly negative light with the election imminent. Stocks have been falling as coronavirus cases rise and the president campaigns around the country accusing Democrats of focusing obsessively on “covid, covid, covid” in their quest to deny him a second term.

“The American people are suffering, and they want us to come to an agreement to save lives, livelihoods and the life of our American Democracy as soon as possible,” Pelosi wrote. “In light of these challenges, I respectfully await your attention to these urgent matters."

Congress has not passed any new economic relief or health-care help for the coronavirus since April. Trump has proved an erratic force, at times calling off talks altogether only to urge an even bigger number than the $2.2 trillion bill approved by House Democrats at the beginning of the month.

Senate Republicans have shown little interest in approving a big new deal, and McConnell advised the White House not to make one before the election.

Government-wide funding expires Dec. 11 meaning Congress needs to pass a new spending bill before then -- and Trump has to sign it -- to avert a partial shutdown. It’s possible that any spending bill could include some covid relief measures.

Jeff Stein contributed to this report