When Lord Salisbury said that “delay is life”, he was voicing a doctrine of conservatism that sought to hold back the tides of change for as long as possible. But the phrase has another value, expressing an enduring truth about political tactics: for a politician under pressure, delay is a vital friend.

Brexiters claim May's plan defeated after No 10 shelves key vote - Politics live Read more

Which is why Theresa May’s decision to delay the meaningful vote scheduled for 7pm on Tuesday evening should hardly come as a surprise. She was faced with a choice between guaranteed defeat, with scores of her own MPs in open rebellion, or the possibility, however remote, that something might come along in the next few days to get her out of that jam. The survival instinct of most politicians, perhaps even most human beings, would always be to swap certain disaster now for the uncertain possibility of something less bad later on. And that is what May has done.

She may still, eventually, suffer a crushing defeat on her Brexit withdrawal plan, followed by Tory MPs bringing a motion of no confidence in her as Conservative leader or a vote of no confidence in her government tabled by the opposition or both. All those things might happen. It’s just the prospect of them is now not as immediate as it was. She has bought herself some time.

But it has come at a steep price. First, she has taken an axe to the already broken credibility of herself and her hapless government. A matter of hours after her senior ministers were on the radio insisting the vote would go ahead, she has made them (and therefore herself) look like liars or fools by reversing that decision. Put it alongside May’s flat insistence in her first year as prime minister that she would not call an early election, only to break her word by calling a snap election for June 2017. From now on, all her firm declarations and solemn vows will be dismissed as hollow, empty words. Perhaps she’s not going to remain in Downing Street long enough for this to matter. But her credibility is shot.

The second price will not be paid solely by her or her party, but rather by the country. For Britain needed the catharsis of Tuesday’s vote. Not for therapeutic reasons, but rather to begin the process of escape from the Brexit quagmire. The vote would have been the first stage in a much-needed process of elimination, whereby MPs would begin to confront the various options and eliminate them one by one.

May would have been defeated. Labour might then have tried, as they have promised, to bring down the government and trigger a general election. That effort would almost certainly have failed. And then the Commons could have got on with the serious business of assessing the Norway-plus scenario and a second referendum, eliminating one or the other until finally a last option was left standing.

Theresa May postpones Brexit deal vote Read more

Now that process is itself delayed. Which means MPs are leaving themselves too little time. Remember, if the clock runs out and no plan has been voted on and agreed to by parliament, then the UK simply crashes out of the EU with no deal on 29 March 2019 – with all the economic and social calamity that that entails. That is the default. That’s what will happen unless MPs can forge a consensus around an alternative action. And now they have less time to find it.

So I don’t blame the Tory MP, a former ally of the prime minister’s, who texted me to say May’s delay “looks shabby and defensive, and as if all that matters is the PM’s own survival”. She has chosen delay to save her own political life. But the country has taken another step towards the precipice. And we are running out of time to find our way back.

• Jonathan Freedland is a Guardian columnist