What an irony that Prime Minister Theresa May’s crisis over Brexit is coming to a head on the 28th anniversary of the fall from power of Margaret Thatcher. If only the Iron Lady were alive today.

She was challenged for leadership in November 1990 by fellow Tory Michael Heseltine. His perfidy fell short of toppling her outright, but Mrs. Thatcher failed to secure the margin needed to survive the vote. So a further vote of confidence became necessary. After consulting colleagues, Mrs. Thatcher concluded she lacked the support to see off the second round.

What was Mrs. Thatcher’s political sin that turned her caucus against her? Obstinacy in the face of growing resistance to a poll tax that levied rates regardless of one’s ability to pay was the catalyst for her removal, say opponents, who did not lack for self-justification.

She had always been viewed by her parliamentary party as an outsider in the old boys’ establishment. Her program of privatization and deregulation set the bien pensants’ teeth on edge. This “Old School” was quite at ease with managing Britain’s decline on the world stage. The poll tax revolt was merely a ready excuse.

Mrs. Thatcher was able to corral support with the backing of Britain’s middle-class, encouraged by her agenda of home-ownership, free market reforms, and patriotic agenda to make Britain “Great” again. Sound familiar? Retaking the Falkland Islands and staring down Gorbachev’s Soviet Union were two notable successes.

Those were not the only source of tensions. There was also the European Union. Thatcher had gone to Bruges, Belgium, to sound her concerns about EU statism. He rankled her colleagues Geoffrey Howe and the Chancellor, Nigel Lawson, by resisting not only monetary union but their monetary machinations.

In a way, it could said that one reason Thatcher was defenestrated was her determination to stand up to the Eurocrats. Mrs. May is the opposite. She is now vulnerable because she has been unwilling to stand up to them.

Mrs. May and apologists can enumerate the concessions they have won from the EU. Regaining control of Britain’s borders. Of Britain’s laws. Of money transfers. Of policy respecting agriculture and fisheries. Never mind that taking back national sovereignty is talked down as “concessions” rendered up by EU mandarins.

The resumption of sovereignty just isn’t complete. The customs union remains unresolved. It is the weak link that renders all other so-called victories hollow. It is an incomplete Brexit. It is Brexit in name only.

Mrs. May would have Britons believe she acts in their best interests. Edmund Burke’s speech to Bristol’s electors set the “top-down” template. He argued that a representative “owes you, not his industry only, but his judgement.” For Burke, this trust was betrayed if, instead of being guided by his own wisdom, an MP “sacrifices it to your opinion.”

How far, though, does this axiom apply in the early decades of the twenty-first century? Burke’s contemporary Adam Smith advocated rolling back the state as much as possible, whereby “natural liberty establishes itself of its own accord.” Government is thus “discharged from a duty” and “innumerable delusions . . . for the proper performance of which no human wisdom or knowledge could ever be sufficient.”

Appeals by Mrs. May to be a steward of British interests fall flat. The people themselves know wherein their interests lie and voted in 2016 accordingly. So why are Conservative MPs hesitant to send letters of no-confidence to the party’s 1922 Committee? It takes 48 to trigger a leadership review.

Should this be so hard in respect of a premier who betrayed the people’s vote to exit the EU? She has advanced a draft withdrawal agreement that surrenders hard-won rights without any avenue for redress. Worse, she has staked her premiership to an agreement with doubtful chance of success in Westminster, warning MPs that the alternative is not “no deal” but “no Brexit.”

During the Rump Parliament Oliver Cromwell had the brass to tell MPs frustrating his will: “Depart, I say; and let us have done with you. In the name of God, go!” Where are the Conservatives with the gumption enough to tell a Prime Minister frustrating the will of the British people — frustrating the Brexit promise — to go?