Nick Boles in a former Planning Minister and Education Minister, and is MP for Grantham and Stamford.

A Brexit that works: it’s not much of a rallying cry, I admit. But it’s what the British people need and what the overwhelming majority of Conservative MPs want to achieve. Although there are a few zealots on both sides of the debate, most people in the parliamentary party are pragmatists. We want to deliver the referendum result without damaging business confidence, the unity of the United Kingdom or peace on the island of Ireland. Because we are not seduced by dreams of a Brave New World, we are cautious about giving up current advantages for the untried and untested. But we also know that just because something hasn’t been done before doesn’t mean it can’t be done in future, and are optimistic that time, imagination and a spirit of constructive collaboration with our European partners should enable us to develop and implement modern systems that work.

It is right that we aim to replace our membership of a customs union with the EU with a new arrangement that gives us the freedom to run our own independent trade policy. But we should not rush this tricky fence. As Conservatives, we prize our reputation for prudent economic management above all else. The only thing that would guarantee a Corbyn victory in 2022 would be if we sacrificed the economic wellbeing of the British people on the altar of some half-baked fantasy of borderless free trade. We must not put the success of our car, aerospace or pharmaceutical manufacturers in jeopardy to meet an artificial political deadline.

That is why I am proposing an extension of the transitional customs union that we will join when we leave the EU in March of next year. I believe it should last for a maximum of three years until the end of March 2022 (though we could bring it to an earlier close if the new arrangements are ready sooner.) That way we can still deliver Brexit in full by the time of the next election, while giving British business the benefit of a gradual transition to a robust new system.

On Monday, Conservative MPs were told that the technologies and systems to deliver maximum facilitation at the UK border are novel, and will not be fully operational by the end of the transition in December 2020. I am happy to support the Prime Minister’s decision about our future customs arrangement – so long as she adjusts the political timetable to reflect the reality on the ground. But if the Government insists on driving through an unrealistic policy simply to satisfy the demands of a few of my more ideological colleagues, I will find myself in the division lobbies voting against my government for the first time in my parliamentary career.

Last year, I left hospital in a wheelchair after an especially nasty bout of chemotherapy to vote for the bill that triggered Article 50 and the start of Brexit negotiations. I did so because I believe that it is my solemn duty to respect the result of the referendum and deliver Britain’s exit from the European Union. I am still determined to discharge that duty. But I will not vote for speculative measures that will harm British businesses and cause chaos at our borders. I will vote for a Brexit that works.