Parliament voted to pass the government’s new withdrawal agreement bill at its second reading on Friday. After almost a year of Commons struggle, Boris Johnson is now dominant and can “get Brexit done”. Once Britain ratifies the article 50 withdrawal agreement that Mr Johnson renegotiated with the EU in October, it will be over to the European parliament to do the same. Mr Johnson will take this country out of the EU at the end of next month.

The psychological impact of breaking common ties with the continent, forged over four decades, will be profound; not least for Labour, which since the late 1980s has been a party that argued the European project was, on balance, good for this country. On that issue it was right. Given the social market model of the EU, the continent could stand up to the forces of the globalised market in a way that a single nation could not. It was also an appealing geopolitical project where trade unions are social partners, citizens have fundamental rights that can be defended, and states can act collectively to defend their shared interests.

On Friday six Labour MPs rebelled and voted for Mr Johnson’s deal. Another 32 Labour MPs abstained. While the Labour party ought to accept that the tragedy of Brexit will happen, it should not accept the prime minister’s terms at face value. Mr Johnson’s new bill prohibits extending the UK’s transition period beyond the end of next year. A complex free trade agreement between the UK and EU is supposed to be worked out during this time. This is a ridiculous position given that such deals can take up to a decade to complete. The best one can hope for in 2020 is a “bare bones” UK-EU deal. The UK is determined to end freedom of movement. That means UK access to the single market will be very limited. This is stupid economics, but clever politics. It gives the prime minister leeway to push for a small-state, deregulated Britain and forces his opponents in Labour to appear like Brexit blockers as they try, rightly, to curb Mr Johnson’s worst excesses. During this essential act of opposition, Labour must avoid being cast as remainers – or rejoiners.

Whoever ends up leading the opposition should take a leaf out of the book of 19th-century Tory prime minister Benjamin Disraeli. It was said that he “discerned the Conservative working man in the inarticulate mass of the English populace, as the sculptor perceives the angel imprisoned in a block of marble”. The next Labour leader must be able to take a hammer and chisel to the party’s Brexit policy to shape it around the social needs and economic instincts of those, usually the poorest, in society who will be hit hardest by departing the EU. Labour cannot shackle itself to Mr Johnson’s hard Brexit. To do so would in effect be offering up the party’s wrists so Tory handcuffs can be applied.

Mr Johnson’s majority is also a weakness. The toxic partisanship of the previous parliament was to some degree fuelled by close competition for power, not just different opinions over the role and scope of government. In time the Labour party ought to seize the chance to capitalise on discontent with Mr Johnson on any number of topics. For a few years, Labour will not have to address questions about how to reconcile competing public goods or how to deal with limited resources. The Tories will have to answer these questions, and make hard choices. The next Labour leader’s task is to exploit the difficult terrain created by leaving the EU to transform British society. Will this be easy? No. But it will be necessary.