LONDON — It’s Friday, March 22, a week from Brexit, and Britain is hurtling toward the cliff edge.

Theresa May has arrived back in No. 10 Downing Street after a last, desperate attempt to avert disaster ended in acrimonious failure at the European Council summit in Brussels.

EU leaders have called a crisis session to prepare an emergency package of support for Ireland. Donald Tusk, the Council president, has launched another angry attack on the U.K., while insisting there is still time to postpone Brexit.

The markets are in turmoil, protests outside the U.K. parliament are turning nasty and Buckingham Palace is on the phone demanding to know what is happening.

Inside her study in No. 10, May sits alone, a glass of Penderyn whisky untouched on her desk. She knows she cannot delay the decision any longer: hunker down for no-deal or accept defeat and return to Brussels requesting a delay?

Her choice: the economic catastrophe of no-deal or the national — and personal — humiliation of a last-minute climbdown to ask Brussels for a Brexit delay.

The most remarkable fact of British politics today is that no one knows which way the prime minister would jump in this scenario: Not her Cabinet, her closest advisers nor her lifelong friends in parliament.

The woman who runs Britain in its gravest hour of crisis since 1945 remains almost uniquely unknown for a prime minister.

After six years as home secretary and three as prime minister, her seemingly impenetrable exterior remains intact, shielding from view whatever lies beneath: the core motivations, ambitions and fears of a leader whose choices will define the U.K. for decades to come.

In interviews with MPs, Cabinet ministers and the most senior government officials who know her best, none were able to say which way the prime minister would jump. Her choice: the economic catastrophe of no-deal or the national — and personal — humiliation of a last-minute climbdown to ask Brussels for a Brexit delay.

“The only person she will have spoken to about that is Philip [her husband],” said one MP who has known her for decades.

In Westminster, Brussels, Dublin and Berlin, the question is the same: "She wouldn’t ... would she?"

She wouldn’t

Around the Cabinet table, there is a nervy assumption May would always back away from no-deal in the end, by applying for a delay to Britain’s exit.

Revoking Article 50 is a non-starter, most of her colleagues assume. Any attempt to unilaterally withdraw the U.K.’s notice of its intention to leave the EU would be fiercely opposed by the Cabinet, given that the European Court of Justice ruling in December means such a move would be deemed all-but irreversible.

British government is Cabinet government — the prime minister is merely the first among equals. Without the support of a Cabinet, a prime minister cannot survive.

The obstacle to revoking Article 50, however, is legal as much as political. Even revocation with Cabinet support does not change the law, as set down by the EU (Withdrawal) Act, under which EU law ceases to apply in the U.K. from 11 p.m. on March 29. To remain in the EU but not abide by its law would cause a crisis of its own. In other words, May alone cannot stop Brexit — only parliament can.

The Cabinet, though, can authorize the PM to ask for a delay. Few believe they would not. And the assumption is that in such dire circumstances, the EU27 would unanimously agree such a request. Under the terms of the EU (Withdrawal) Act, the government can amend exit day to delay Brexit without primary legislation.

At the heart of the argument is the claim that May is first and foremost a patriot consumed by her duty to protect national security and the union between England, Scotland, Wales and Northern Ireland.

“All of the Cabinet, bar, perhaps, Penny [Mordaunt, the international development secretary] or maybe Andrea [Leadsom, leader of the Commons], accept that no-deal is a disaster,” one Cabinet minister who agreed to speak to POLITICO on condition of anonymity said. “They say with complete confidence she will never do it, but very few of them are prepared to actually say it [themselves].”

In EU capitals, the same assumption reigns.

At one high-level dinner of diplomats and journalists, one ambassador for an EU27 country declared: “The only thing I know for certain is that no-deal can’t happen.”

May’s former chief of staff Nick Timothy, one of the few people who has ever genuinely gotten close to the prime minister, declared in a recent Daily Telegraph column that May does not have it in her to go for no-deal.

“After many years of knowing the Prime Minister, I do not believe that she would willingly take Britain out of the EU without a deal,” he wrote.

At the heart of the argument is the claim that May is first and foremost a patriot consumed by her duty to protect national security and the union between England, Scotland, Wales and Northern Ireland.

Labour’s Keir Starmer, who worked closely with May as director of public prosecutions when she was home secretary, has publicly insisted the PM takes her national security considerations too seriously to actively pursue a no-deal Brexit, which would leave Britain’s security services outside key intelligence networks.

Tory first

Not everyone is so sure.

On January 21, the Evening Standard, the newspaper edited by former Chancellor George Osborne, published an editorial declaring May would go for no-deal to protect the Tory Party.

“Mrs May will never be the Prime Minister who forms a parliamentary majority at the expense of her party,” the editorial declared. “She will always, when the chips are down, put short-term Conservative unity first above what the national situation demands.”

“That’s the story of her career as a Tory super-activist and the sad story of her premiership,” it concluded.

The attack was brutal, but those who know the prime minister acknowledge it is not without substance.

To understand May, one must understand her relationship with the Conservative Party — a relationship unlike that of any other Tory MP.

"She will always, when the chips are down, put short-term Conservative unity first above what the national situation demands." — The Evening Standard

“For most of us, the Conservative Party is a means to an end,” explained the Cabinet minister. “Theresa is different. She has an attitude to the Conservative Party which is more in common with a lot of Labour MPs. For them, it is something closer to love, to family. For us, you have family and nation, the Conservative Party is just a vehicle. If it’s not working, you change it.”

Not for May.

The prime minister lost both her parents young, has no brothers or sisters and few — if any — close friends outside the party. She met her husband at a Conservative Party ball at Oxford in 1980, where they were introduced by the former Pakistani Prime Minister Benazir Bhutto. The party her family.

“It goes back to childhood,” explains the Cabinet minister, who has remained publicly loyal to her leadership since she took over in 2016, but believes her flirtation with no-deal is dangerous. “It’s what she does at weekends. She doesn’t really have anything else. It’s one of the reasons she’s popular with the voluntary party.”

The Cabinet minister said this attitude was encapsulated in her parting shot at Osborne when she sacked him. She told him to spend some time getting to know the party.

A second MP who knows May well agrees that the relationship is more intense than with almost any other Conservative MP. “I’m not conscious that she has a big network of friends outside the Conservative Party,” the MP said.

For this reason, May is especially conflicted about the impending crisis. “She feels she owes the Conservative Party a duty as well as the country,” the MP said.

Her husband, Philip, is similarly inclined, according to some in the party.

Andrew Gimson, the associate editor of activist site Conservative Home, has written that Philip May’s “instinct” will always be to preserve Tory unity. It came after reports that May’s chief of staff Gavin Barwell blamed Philip for scuppering attempts to find a consensus deal with Labour.

Some say they believe Philip could again nudge her toward a tough stance. An Oxford friend told Gimson: “Philip is politically combative and not terribly subtle. At certain points he will say, ‘You fight them darling.'"

Together, the fear of a government led by Labour's Jeremy Corbyn is worse than the fear of no-deal. “Her view is that if we split the Conservative Party, you risk Corbyn getting in,” the Cabinet colleague said. “There’s a failure of imagination, that somehow the worst won’t happen [in a no-deal].”

Delay

There is also the threat that a no-deal Brexit would pose to the union of four nations that make up the U.K.

“No deal means the rapid break up of the U.K.,” one senior government official said. “[Scotland's First Minister Nicola] Sturgeon will organize a unilateral independence referendum and there will be calls for a border poll in Northern Ireland.”

And then there is May's own future.

“It would be wrong to suggest she does not adore being prime minister,” according to Rosa Prince, her biographer. “[It is] a position she craved for many years and, more importantly, thinks she deserves. Every evidence indicates she believes, quite simply, that she is the best person for the job.”

In May’s mind then, both no-deal and no Brexit risk a split in the Conservative Party, a Corbyn government to wreck the country and the end of her premiership. The only sensible decision: to delay.

In May’s mind then, both no-deal and no Brexit risk a split in the Conservative Party, a Corbyn government to wreck the country and the end of her premiership.

Faced with such a choice, the only sensible decision is to delay.

“She would do literally everything she could to stop that [choice] happening,” said one friend. “Ultimately, though, it’s not in her gift to choose party over country. Parliament will move for her if she doesn’t."

The friend added: “She has to do everything she can to give the party the chance to bring about its own version of Brexit."

One of her closest parliamentary allies predicted that May would "push as hard and long as possible" to achieve a deal that her party and her parliamentary allies the Democratic Unionist Party can support.

"She will use every last minute of time before she has to make that choice," the ally said, adding that in the end, she may refuse to make it until it's too late to stop no-deal from happening.

"She will delay and delay — she may not make that choice and go for no deal. I don’t think even she knows.”