Quentin Letts is a political columnist and theater critic for the Daily Mail and the author, most recently, of “Patronising Bastards: How the Elites Betrayed Britain.”

British prime minister Theresa May makes your average Atlantic mollusk, gripping its wave-smashed rock-pool, look like an amateur. She was buffeted but unmovable on Thursday as she withstood three hours of questions from a despairing House of Commons. The prime minister had just published her draft agreement for Britain’s exit from the European Union. It went down like a rotten prawn.

For two years, May had been promising a Brexit that would allow Britain to regain full control of its borders, money and laws, all while doing business with the E.U. and striking its own trade deals with non-E.U. countries such as the United States. Her draft agreement turns out to be less ambitious. Despite having to pay a “divorce bill” of 39 billion pounds (about $50 billion in U.S. dollars), Britain may remain tied to E.U. rules and trade restrictions for an undefined period.

The draft withdrawal agreement was prepared in such secrecy, cabinet ministers did not know its details until a few hours before they met on Wednesday to approve the plan. That meeting became so bad-tempered, one minister was reported to be in tears and another was shouted at by the country’s top civil servant.

Prime ministers are used to being criticized in the House of Commons but, normally, they can rely on the support of at least half the chamber. On Thursday, May was savaged by all sides: in front of her, behind her, from the left, the right, pro- and anti-E.U. In those three hours, only a handful of members of Parliament pledged support for her plan. Meanwhile, two members of her cabinet resigned. One of them was clever, soft-spoken Dominic Raab, who had been the Brexit secretary. If the guy supposedly overseeing the policy didn’t like it, where is that meant to leave the rest of us?

Over the past year, 17 ministers and ministerial aides have walked out of May’s administration. At times, matters have become so argumentative, the administration has looked less like rational government than it does a bar brawl in a John Wayne film. The latest outburst of (metaphorical) fisticuffs came on Thursday when a caucus of May’s pro-Brexit Conservative backbenchers announced a bid to oust her from the party’s leadership. The first stage of that effort would be a no-confidence vote, for which they need 48 signatures. Steve Baker, organizer of this insurrection, told reporters on Friday he was “pretty close” to that figure. If he is struggling to find the last few signatures required to reach 48, it is probably only because Conservatives are wary of creating such a national crisis that could somehow result in Jeremy Corbyn, the Labour Party’s radical left-wing leader, becoming prime minister.

Through it all, the prime minister has been stolidly dutiful, seldom varying the formula of her replies or shifting from her technocratic positions. Questioned about the plot to topple her from the party leadership, May does not raise her voice or narrow her eyes. Theater, verve, blood and guts: these are alien to the May repertoire. That is both her strength and her weakness. It makes her look resilient — only a cur would deny the physical stamina she has shown — but it also makes her seem deaf to political reality. The likes of Baker allege that, though she is inflexible at home, she bent like a hazel twig in her negotiations with the E.U. Brussels certainly appears to be cock-a-hoop with the draft she negotiated.

The prime minister insists she can persuade the House of Commons to ratify this much-mauled plan. The arithmetic of a hung Parliament suggests the sharp opposite. There are 650 members in the Commons. Of the 315 Conservatives, possibly a quarter will vote against May’s E.U. plan unless it is changed. The 10-seat Democratic Unionist Party, which holds the balance of power in the chamber, also opposes the agreement, as do most members in the opposition. May’s party activists are increasingly mutinous, wondering why she doesn’t just swing to a position that reflects better the will of the people who so stunningly voted in 2016 to leave the E.U.

Britain’s membership in the European Union is scheduled to cease on March 29. Time for renegotiation is dauntingly short, yet Westminster is log-jammed, with May refusing to try to alter her deal. She says there are only two alternatives: “no Brexit” or “no deal.” Though former prime minister Tony Blair is calling for a second referendum, “no Brexit” could seem a denial of the unprecedented turnout for the 2016 vote; nor is there any firm evidence that voters have changed their minds about membership in the E.U. “No deal,” according to some forecasters, would cause grave economic harm.

Result: political inertness. Meanwhile, the Brexit storm continues, the waves crash all about, and mollusk May remains in place.