THERE was disappointment all round after the Peterborough by-election result – not just in Nigel Farage's Brexit Party. Labour Remainers had hoped to use a defeat to force Jeremy Corbyn to properly back a Peoples Vote on Brexit. Instead, the Labour leader is able to say, half credibly, that his policy of “constructive ambiguity” (fence-sitting to you and me) has worked.

Brexiteers in the Tory Party had also privately pinned hopes on Nigel Farage, in expectation that a BP victory would urge terrified Conservative MPs to support the no-deal populism of Boris Johnson. The voters of Peterborough however did not to oblige. It wasn''t the plague on all your houses that was expected but a grudging acceptance that Labour was the least worst party on the night.

At any rate, the by-election showed that parties still count. It was Labour's ability to devote the full energies of a party machine to this contest that delivered their victory. They have the data on where Labour voters live and they have the person-power to ensure that they're contacted and urged to vote. Even driven to the polling stations in some cases.

The Brexit Party lacks that kind of organisation, since it is only three months old and doesn't even have a policy platform, let alone legions of loyal party workers. But no one should be in any doubt about the significance of the result. It showed that the big parties still have a huge problem. Both lost to the Brexit Party – but the Tories lost a lot more votes than Labour did.

It was, if not a plague on the Tories, then certainly a bad case of political measles. And richly deserved, given the shambolic state of the party leadership campaign. It came in the week that a credible Tory candidate for prime minister, the former Brexit Secretary Dominic Raab, seriously suggested abandoning parliamentary democracy in order to deliver a hard Brexit.

His cunning plan of “proroguing” or suspending parliament in October, to prevent MPs voting against a hard Brexit, originated in reflections on the constitution by the Institute for Government, a non-party think tank, in April. The Prime Minister has the prerogative to suspend parliament in the weeks before a general election to allow MPs to campaign. Hard Brexiteers in the Tory Party thought of using prorogation to prevent a Remain-supporting House of Commons from blocking a No Deal Brexit on 31s October.

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“Oh no you don't”, responded the Speaker, John Bercow. He made clear that under our democracy parliament is sovereign, and if an attempt were made to suspend parliament, he would just unsuspend it, by letting MPs hold a vote on seizing the legislative agenda as he did in March. Short of an actual military coup, that would prevent any Tory PM getting their way.

So was this the nadir of the Tory leadership contest? Have we hit bottom yet? Is Boris Johnson back in his box? The answer is probably no on both counts. This result was bad enough for Conservatives to realise that in many relatively safe seats the Brexit Party could do serious damage in a general election. Unlike a by-election, which is fought mostly on the ground, a general election is largely fought on the air waves, through the media. Nigel Farage, like him or loathe him, has mastery of the air war.

So, Tory MPs now realise that they simply have to force through Brexit or risk a historic election defeat, similar to that of Kim Campbell's Canadian Conservative Party in 1993, when it was reduced to 2 seats. Above all, the next Tory PM has to avoid triggering a general election. It's not easy to see how these aims can be reconciled, however. Assuming that John Bercow blocks prorogation, how would Prime Minister Boris Johnson (assuming he wins) actually play the No Deal card?

As the days and hours tick down to 31st October, we can be pretty sure that PM Boris will not have succeeded in negotiating a new Withdrawal Deal with Brussels. The EU negotiating teams have been disbanded, for a start. There will be no Jean Claude Juncker or Donald Tusk to authorise new negotiations, since both are standing down as President of the European Commission and Council respectively.

This leaves the PM and parliament in a game of constitutional chicken. Boris Johnson would presumably win any no confidence vote should Labour engineer one in October. Tory MPs will back him to avoid a general election. Their coalition partners, the DUP, will back Johnson to avoid opening the way to a Jeremy Corbyn government sympathetic to the idea of a united Ireland.

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Now, Johnson is pledged to threaten a no deal Brexit, but he hasn't actually promised to carry it out against the will of parliament. How could he? We don't live in a dictatorship. Everything Johnson says should be weighed against the possibility that parliament forces him to reject leaving the EU without a deal. In that event, he'd probably throw his hands in the air and say: what can I do? Parliament has spoken.

He has ruled out a referendum, and therefor faces the choice of a further extension, a general election, resurrecting May's Withdrawal Deal or Revoking Article 50. Parliament is opposed to revocation, just as it is opposed to no deal. A general election is out of the question, so Johnson will be left with the only deal that is on the table, which is the one that caused his predecessor's downfall. What does he do?

Well, in these circumstances, Boris Johnson's lack of principle and his populism could be his deliverance. He will presumably repackage the existing Withdrawal Deal with lots of Brexit ribbons, and promise to drive a hard bargain over the future trading arrangements.

Everyone has forgotten that the Withdrawal Deal has nothing directly to do with questions like the customs union or regulatory alignment to the single market. It is simply about money, citizenship and the Irish border. Johnson will say that his ambitious plans for a WTO free trade deal begin the day after the Withdrawal Deal is passed by parliament. Only then, he'll say, can we unblock Brexit.

Of course, he would be repeating Theresa May's line, but this is politics. Sometimes the person who articulates a policy is as important as the policy itself. Tory MPs will realise that there is no alternative to Boris Johnson – he's their best their last shot. And if they don't back him, then there will be another catastrophic delay to Brexit, or a Labour government, which is worse. Indeed, Boris might even threaten to effectively Revoke Article 50, on the grounds that the EU will not agree a further extension and he would be bound by parliament so to do.

Boris Johnson Revoking Article 50? What a thought! Outlandish and ridiculous. However, remember that, when Boris Johnson was considering whether or not to lead the Vote Leave campaign in 2016, he wrote two articles for the Daily Telegraph. One gave his arguments for backing Brexit. The other gave equally cogent arguments for Remain. Mr Johnson is someone who will say whatever is needed to advance the Boris brand.