High noon. Mexican standoff. Last chance saloon. There’s been no end of opportunities to deploy metaphors drawn from the Wild West to describe Brexit. This is kind of appropriate since the benighted enterprise was triggered by a bunch of cowboys and peddled by snake-oil salesmen.

In another way, talk of shootouts and showdowns is a bad journalistic habit of which I’ve been occasionally guilty myself. Describing Brexit in these dramatic terms suggests we are about to reach some kind of resolution and the end credits can finally roll. Yet we never do. Every exchange of gunfire at the Not O.K. Corral is followed by the grim realisation that the plot has not been advanced at all. We are still stuck where we have been marooned for months: without a deal that parliament will pass and without a proved majority for any alternative. In Brexitland, it is always crisis and never catharsis.

What goes for the process is true also of the woman supposed to be in charge of ensuring that Britain departs the EU in a non-chaotic fashion. I heard a Conservative MP remark recently that the prime minister was “in the last chance saloon”. Calamity May has been sitting in that unhappy establishment for so long that the bar has long since run out of whiskey and the pianist is covered in cobwebs. More than a month after she went down to a historic parliamentary defeat, and after another humiliation at the hands of MPs in the past few days, Mrs May is still trying to sell the deal the Commons rejected by an unprecedented margin and the EU says it won’t rewrite to please the Brexit ultras.

Step back to look at the big picture and you can see that Britain is trapped in a grotesque situation. There are just 40 days left before one of the world’s top 10 economies is due to terminate an intricately complex 45-year partnership with its closest neighbours. The leaders of this country have devoted 32 months to negotiating the withdrawal. And we still have absolutely no idea under what arrangements, if any, Britain will be trading and dealing with its neighbours in the very near future. The possibility that we might crash out at 11pm on 29 March with no agreement at all remains a live one.

This limbo status applies to much of the rest of the world as well because our commercial relationships with other countries have been managed through membership of the EU. Britain has 69 trade agreements with non-EU states that the government hopes to “roll over”. Liam Fox has had to admit that all the time he has spent in airport VIP lounges has so far yielded only a small minority of these vital arrangements, covering less than a seventh of the £117bn of British trade with the countries involved.

Facebook Twitter Pinterest ‘We can all see what Mrs May is up to. There’s no secret cunning about her plan.’ Photograph: Steve Parsons/PA

One of the very few consolations of Brexit is the regular bulletins of failure that have to be issued by its leading proponents. The international trade secretary and evangelist for a “Global Britain” has agreed terms with the Swiss and the Israelis. Oh, and the Faroe Islands. You can’t get much more “global” than the Faroe Islands, can you? He hasn’t secured agreements with such non-trivial countries as South Korea and Japan. Cargo ships will this week depart British ports for the far east, and vice versa, and their captains will have no idea what terms and tariffs will apply to their goods when they reach their destinations. They may be told they can’t even be landed.

We can all see what Mrs May is up to. There’s no secret cunning about her plan. Despite the manifold weaknesses of her position, she still has control of the process and is using that power to take Britain closer and closer to the cliff edge of a no-deal exit. She persists with this perilous gamble in the belief that, when MPs are staring into the abyss, enough will be scared into backing her deal. We should not discount the possibility that this might work if the EU offers enough tweaks, some of the Brexit ultras blink and sufficient Labour MPs can be seduced with promises of cash bungs to their constituencies. If she pulls off a late win in this fashion, some will briefly hail her as a tactical genius. Yet even if she succeeds in railroading her unloved deal through the Commons, this will guarantee terrible trouble further down the line. And if she fails? Britain will be left dangling over the cliff edge.

Jeremy Corbyn was not wrong to say the prime minister “continues to recklessly run down the clock”. What he did not say is that he is complicit in the deliberate exhaustion of time. I mean this in two ways. A different type of Labour leader would have been able to reach over to some of the moderates on the Tory benches to mould a better outcome. But Mr Corbyn is not a man who will work with any kind of Tory and he is not the kind of Labour leader any Tory will trust. Most importantly, he doesn’t want to stop Brexit. He wants a “Tory Brexit” that he can then condemn. His endless prevarications are designed to avoid committing to the second referendum that the vast majority of his members and most Labour supporters yearn for, but he will avoid if he possibly can.

The clock would not be running down so dangerously without the active or passive connivance of MPs as a body.

A lot of the blame for Britain’s drift towards disaster lies with the cynical manoeuvres of the two main party leaders, but culpability doesn’t entirely rest with them. Mrs May and Mr Corbyn are, in the end, just two people. There are another 648 MPs and each bears responsibility for how he or she acts – or doesn’t. The clock would not be running down so dangerously without the active or passive connivance of MPs as a body. A large majority grasp that continuing uncertainty is racking up an ever higher bill in lost investment and relocated jobs. Even if the crash-out scenario doesn’t ultimately materialise, the threat of it is has already forced many companies to make decisions that will be irreversibly damaging to the country’s future prosperity. Business investment has fallen for four consecutive quarters. Most MPs also know that a no-deal outcome threatens to be terrible for many of their constituents. Any parliamentarian capable of reading a calendar can see that we are running horribly short of time to avoid a calamity Brexit. And yet, for a variety of reasons, mainly timidity in the face of this national emergency, the latent majority in the Commons for a non-disastrous outcome has not been willing to act.

Parliament has declined opportunities to give binding instructions to the government that there cannot be a no-deal outcome. When recently offered the choice, MPs voted against taking the process out of Mrs May’s hands. Last week, parliament effectively decided to give her another fortnight to try to fettle her agreement, even though she still has not told MPs, and perhaps does not even know herself, what changes she is going to seek when she flies to Brussels this week. So it is not just the two party leaders who are running down the clock – it is also parliament as a collective.

The senior teams in both the main parties should be searching their consciences. The shadow cabinet has not asserted itself by demanding that Labour satisfies the wishes of its members and throws its weight behind a second referendum. They privately point the finger at Mr Corbyn’s Eurosceptic inner circle who, as one shadow cabinet member put it to me, have the leader “under close guard”. Rather than blaming others to excuse their own failure, senior Labour politicians should be acting.

The sensible ministers in the cabinet know that this nightmarish limbo is hurting the economy and wounding Britain’s reputation with the rest of the world. Growth last year was its weakest since the financial crash. Senior ministers also understand that a no-deal outcome will be a catastrophe. Yet they have so far proved incapable of forcing a change of strategy on the prime minister. There have been regular predictions that at least six members of the cabinet are poised to resign if Mrs May doesn’t change course. Yet each time they have been presented with an opportunity to act, they have allowed it to pass. The generous way to describe these ministers is as people waiting for the right moment. The unkind way to categorise them is as ditherers and cowards.

The next deadline for everyone’s diary is 27 February when Mrs May will have to report to MPs on what she got out of her latest talks with the EU and there will be another chance for parliament to act. There is fighting talk from the sensibles in the government that this will be the moment when they will finally assert themselves, and by quitting if necessary, to create a majority to halt the slide towards a catastrophe Brexit. High noon approaches. Again.

To me, it feels a lot more like one minute to midnight.

• Andrew Rawnsley is an Observer columnist