We are approaching Brexit crunch time. Everyone is going to come under intense pressure to agree a “reasonable deal”, Labour MPs especially. They should resist. There is no “reasonable deal”. There is the pointless, the painful or fudge through postponement of the core issues. Each option is bad.

MPs should vote it down and give the people the final say. This will be fiercely resisted for a mixture of good reasons – causing more turmoil and division – and bad reasons – the anxiety that people might change their minds. There will be a vast effort over the coming weeks to do “the deal” and then force it through parliament on the basis that it ends the uncertainty, allows “the will of the people” to be followed and is better than the nightmare of no deal. Business will heave a sigh of relief. Some Labour MPs and Tory rebels will be attracted by it. “Best of a bad job” will echo through the corridors of power. And Europe will be tempted.

With all my experience of politics and government I completely get it. Never underestimate the desire of systems to produce a result. But here’s the flaw: “a deal” is a chimera. There is no “deal”. There is a choice.

The government has made a set of incompatible demands, in which politics clashes fundamentally with economics. They want a frictionless border in Ireland. That can only happen if Northern Ireland remains in the customs union and single market, at least for goods and agricultural products. But they want the UK to leave the customs union and single market. However, they also want Northern Ireland and Britain to be in the same relationship to Europe as each other. And they made a rash commitment last December that the Northern Ireland issue would be resolved as a part of the withdrawal agreement with the border frictionless and with a backstop to guarantee it.

There is simply no answer to the Irish issue. The government will be forced to agree the “backstop” or imagine a scenario in which Northern Ireland will be in a different relationship with Europe and tied to the south. For the trading relationship between the UK and Europe, there is a choice arising out of the unique nature of the single market, which alone of all the trade agreements in the world seeks to create one comprehensive regulatory environment for goods and services. This has boosted European trade and spawned a set of interlocking supply chains, service-sector commerce and investment decisions.

Britain has probably gained more from this market than anyone. So wrenching us out of it gives rise to this dilemma: stay in step with Europe’s rules to minimise economic damage or break free from those rules and suffer the damage. The first is pointless and the second painful. Pointless versus painful is the choice.

You can postpone the choice by fudge, but you can’t change it. Europe will never allow us access to the single market without obeying its rules, adjudicated by the European court of justice. Yet Theresa May needs the political wiggle room so it appears that we can.

So, Chequers was a choice, camouflaged as a “deal”. It chose pointlessness. But to keep as many Brexiters on board as possible, it’s not called the single market but a “common rule book”, and a theoretical right to diverge is stated though it is never meant to be activated. Here is the extraordinary statement in the Chequers presentation: Britain, it says, should agree to keep all existing European regulation because that is “in the UK’s interest”. You may have thought we were leaving Europe because we couldn’t abide these rules but no, we are recommitting to them and as a matter of principle! It goes on to say that, for the future, we will continue to keep to them for goods.

With this Brexit, in the name of “taking back control”, we will literally have lost the control we had! This proposal has virtually zero support in opinion polls, so how could it pass?

Europe will never allow us access to the single market without obeying its rules

Parts of the Tory party just want the misery to end. Brexiters in the cabinet back Chequers because they think they can use the camouflaged language to reopen the debate after March 2019. They can activate the right to diverge; they can say “common” does not mean “the same” – ie revert to hard Brexit. Some Remainers, in both parties, think “do Brexit and try to pull Britain back into Europe later. Europe is torn: fudge, to get the thing through, and negotiate later, rather than force clarity, and therefore crisis, on May.”

I say, in all frankness, this is madness. Decide the matter. Leave or stay but, please, not half in-half out with the battle not decided but postponed to be continued for decades to come. So when Labour MPs consider backing the prime minister because “isn’t a ‘reasonable deal’ better than no deal?”, they must understand that they’re not agreeing a reasonable deal. They are agreeing pointless or painful or postponed.

None of these outcomes will earn the gratitude of their constituents at the 2022 election – plenty of time for all the pennies to drop. The threat of no deal is empty. Suppose the deal is blocked? Suppose a resolution for a people’s vote is also defeated, though I hope and believe it won’t be? All options are still open.

Time has not lessened my sense of the catastrophic effects of Brexit. It has increased it. MPs should vote against the deal while saying to their constituents: “We cannot, in all conscience, agree with this, but the final decision is yours.”

I promise them as someone who used to win elections: no one will lose their seat on this basis. But vote through a botched negotiation that you don’t believe in and the backlash will last a political lifetime.