Every time I think Britain’s MPs have touched bottom, they sink lower.

The House of Commons has just resolved that it will not let Britain leave the EU without explicit permission from Brussels, or, as Europhiles absurdly phrase it, that they will not let Britain “crash out” with “no deal.” With one vote, MPs have destroyed any prospect of an equitable outcome. Eurocrats now know that Britain has only two options: either to leave on humiliating terms, terms that would leave Brussels in charge of its trade policy in perpetuity, or to give up on Brexit entirely.

I’m trying to think of a more foolish and self-harming parliamentary vote. I can’t come up with an example from the past hundred years, or even the past 200. To find a similar level of legislative idiocy, we have go back to February 1775, when the House of Lords rejected Pitt the Elder’s Provisional Act, a measure that would have addressed the grievances of the American colonists and reconciled the two great branches of the English-speaking peoples.

I have previously poured cold water over the idea that support for President Trump and support for Brexit are equivalent phenomena. There are important differences between them: Most Brexiteers, for example, want freer trade, including with China. They resent being stuck in a protectionist European customs union. But Trumpsters and Leavers did have one thing in common. Both believed that that their respective politicians had stopped listening to their electorate, that they had become a remote and self-serving caste.

Everything that has happened since the Brexit vote in June 2016 has vindicated that belief. The moment the result came in, Westminster MPs and Brussels functionaries started working to overturn it. Some did so openly, campaigning for a second referendum or demanding that Britain revoke its legal notice to quit, which is scheduled to enter into force at the end of this month. Others operated more furtively, aiming to ensure that the exit terms were so bad that, in the end, Britain would drop the whole idea of recovering its independence.

Does that sound far-fetched? Listen to what Michel Barnier, the EU’s chief negotiator, told European leaders in 2016, as revealed by the French magazine Le Point: “I’ll have done my job if, in the end, the deal is so tough on the British that they’d prefer to stay in the EU.”

A certain coldness from the EU was to be expected after the referendum. What was not expected was the readiness of British MPs to collude with Brussels in the hope of frustrating the largest vote in British history. Some politicians have maneuvered in the shadows. Others, including two former prime ministers, John Major and Tony Blair, have acted with stunning flagrancy, publicly calling for a reversal of the electorate’s decision.

Their behavior is causing catastrophic damage to Britain’s international standing, to its democratic procedures and, most seriously, to the authority of its institutions. Faced with calculatedly vindictive demands from the EU, including the regulatory annexation of Northern Ireland and a customs union that would prevent Britain from signing its own trade deals, any self-respecting nation would walk away from the table and then make the EU a generous offer on commerce and cooperation on a take-it-or-leave-it basis. Shamefully, Britain’s elected representatives are not prepared to do that.

There is blame enough for all sides. Labour has been focused solely on trying to force a general election. If that means blowing up any credible British negotiating strategy, so be it. But a handful of Conservative Eurofanatics have sided with Labour, or, rather, with Brussels, despite the fact that both main parties promised, at the 2017 general election, to respect the referendum result. Prime Minister Theresa May, for her part, emerged from the vote having lost her majority, her voice, and her authority. Rarely has British politics been in such a mess. No wonder Brussels negotiators feel they can press their advantage.

Imagine, to return to 1775 for a moment, that the Continental Congress had declared that it was not prepared to “crash out with no deal,” and so would not declare independence except with the wholehearted approval of King George III. You can’t imagine that, can you?

This has gone beyond Brexit now. What is at stake is nothing less than the legitimacy of our system of representative government. If MPs are seen to have sided with overseas powers against their own constituents, nothing will ever be the same again.