British Prime Minister Boris Johnson’s plan to suspend Parliament is hardly the “coup” that his more emotional opponents have claimed. Even so, the move is shabby politics, a gamble that might well fail, and an eloquent demonstration of the prime minister’s weakness.

On Wednesday, Johnson asked Queen Elizabeth II to prorogue the legislature for five weeks before beginning a new session in mid-October, a little over two weeks before the Brexit deadline. This isn’t unprecedented or on the face of it unlawful. It still leaves time for the House of Commons to veto a no-deal Brexit if it can muster a majority for that. But proposed at a moment of national crisis, this suspension will be the longest in decades, and Johnson’s stated reason — that it’s necessary to introduce a “bold and ambitious” domestic agenda — is plainly dishonest.

What’s the real objective? The prime minister seems to be banking on two possible outcomes.

One is that he’ll tempt the opposition into calling a no-confidence vote and hence an election. With Labour in complete disarray, and Brexit opponents split on every other matter of public policy, this has a certain strategic appeal. But any such course would threaten only more costly delay and uncertainty over Brexit.

The second rationale is that the suspension, if it isn’t overturned by the courts, will frustrate efforts to stop Britain from exiting the European Union without a deal come Oct. 31. Preserving the possibility of a no-deal exit is the core of Johnson’s Brexit strategy, his main leverage in talks with the EU.

Again, one can see the strategic sense in this calculation. Again, though, it’s grossly irresponsible. A majority in Parliament has already rejected a no-deal exit. Only about 25% of the public supports it —indeed, only half of those supporting Brexit agree with it. It would be the worst possible outcome to this whole misbegotten process, leaving the U.K. poorer, weaker and indefinitely adrift.

More than anything, Johnson has demonstrated the weakness of his own position. He’s an unelected prime minister heading a minority government. With this threadbare legitimacy, he’s facing the most consequential decision a British prime minister has had to make in decades. And his unpopular negotiating position is pointing the country toward calamity. To escape this bind, he’s chosen tactical maneuvering rather than wise leadership.

Johnson’s supporters think suspending Parliament is a cunning move. It’s better understood as an act of desperation — and, if this still counts in British politics, an assault on the national interest.

Editorial by Bloomberg Opinion