LONDON — The gods heard Theresa May’s offer to fling herself into the volcano to save Brexit, and shrugged.

Naysayers are still denying the British prime minister her exit plan. No one can say what it will take to close this deal — or what will happen to May, who promised to resign, sometime in the future, if the deal is approved.

Britain was supposed to be leaving the European Union on Friday. May promised it would happen more than 100 times. That it will not represents one of the great stumbles of any government in postwar Britain.

Instead of Brexiteers celebrating independence day, lawmakers will be debating May’s Brexit deal, again.

But not her total plan — no, only the 585-page withdrawal agreement. That’s the part of the treaty that spells out, in a legally binding way, how much Britain will pay to leave the European Union ($50 billion), how the two-year transition will preserve the status quo for trade and travel (no change), and how Britain and the European Union will treat each other’s citizens in the interim (nobody gets kicked out of anybody’s country).

The withdrawal agreement also includes the controversial “Irish backstop,” an ironclad guarantee to preserve the open, invisible border between Northern Ireland and the Republic of Ireland — with trade-offs that have been a stopping point in the past.

Parliament will not vote Friday on the second part of the treaty, the political declaration, which sets out the aspirations for the future relationship on trade, security and borders.

The hope, from Team May, is that the withdrawal agreement on its own will win over more votes than the overall agreement.

In a sign of how Brexit maneuvering doesn’t tend to get very far, earlier the thought had been that the political declaration was needed to sweeten the withdrawal deal.

Will this new play work any better? The May government is deeply into its improv stage. The government now lives vote by vote — and Friday it is again playing for time.

If Parliament approves a withdrawal agreement by the end of the week, the European Union is expected to extend the Brexit deadline from April 12 to May 22. But Parliament needs to approve both the withdrawal agreement and the political declaration if it wants to avoid crashing out of the European Union without any transition period.

Meanwhile, protesters demanding a just-get-on-with-it Brexit have been marching toward the capital this week, under a “Leave Means Leave” banner unfurled by the arch-Brexiteer, radio personality and President Trump friend Nigel Farage — who has mostly begged off on the marching-in-the-rain bit. These folks at one point numbered a few dozen. That’s compared with the hundreds of thousands who came out to call for a second referendum on Brexit last Saturday.

There have now been a number of “meaningful votes” and “indicative votes,” but Parliament has twice refused to pass May’s withdrawal agreement. On Wednesday, the House of Commons could not muster a simple majority for any of its own eight Brexit proposals.

The very same Parliament members are threatening another go at it Monday. It is possible they will narrow down the options to a mere handful, seeking to know whether the House of Commons might go for a second Brexit referendum or back a “softer” Brexit, say along the lines of Norway’s half-in, half-out arrangements with the E.U.

The votes are nonbinding and could be ignored by the government, as cabinet ministers have warned.

E.U. leaders advise that the withdrawal agreement is not open for more negotiation. It is what it is.

A European Commission spokesman tweeted Thursday: “@EU_Commission takes note of the indicative votes in @HouseofCommons last night. This is part of an ongoing political process in the #UK, which we fully respect. We counted 8 ‘noes’ last night. Now we need a ‘yes’ on the way forward.”

Charles Grant, director of the Center for European Reform in London, spent the past few days watching this endless second-act drama — all buildup, no denouement — from Brussels.

In a tweet, Grant reported the Europeans “think the chances of no deal are high, because they don’t trust the U.K. political class not to screw up.”

On Thursday, former Brexit secretary Dominic Raab — who might be a contender for May’s job — said he still believed it is possible to get concessions from Brussels on the withdrawal deal. If not? Raab suggested “sensible conversations” about leaving with no deal.

Many in Britain were still chewing over May’s “back me then sack me” move, which prompted several Conservatives — some of whom covet May’s job — to signal they would finally be ready to support May’s Brexit deal. But that swing didn’t appear to be enough.

The Democratic Unionists, the small Northern Irish party that props up May’s government and who May is desperate to get on her side, made it clear their problem is not one of personnel. They won’t be voting for the agreement.

“We will continue to do what we can to get the best deal for Northern Ireland,” the party’s deputy leader, Nigel Dodds, told the BBC.

Even though May offered no exit date, there is already intense interest in who might replace her.

Trump weighed in Thursday, wishing “the Brexit movement” well and commending May. “She’s strong, she’s tough and she’s in there fighting,” he said.

Asked about May rival and former foreign secretary Boris Johnson as a possible future leader, Trump replied: “I like Boris Johnson a lot. He’s a friend of mine.”

Broadcasters on Thursday were camped outside of the homes of prominent Conservative politicians, such as Environment Secretary Michael Gove and Home Secretary Sajid Javid.

Nigel Evans, a Conservative member of Parliament, seemed to sum up the mood of the nation when he told the BBC: “All we know about tomorrow is it’s called Friday.”