Seventy-eight years ago this week, the Labour party did the unimaginable: in the early stages of the second world war, when we were fighting for national survival, it turned on the Conservative prime minister Neville Chamberlain and drove him from office.

The decision to force a division in that House of Commons debate — called the Norway debate because it related to the allies campaign to stop the German invasion of that country — is now celebrated. Yet, at the time, it was attacked as opportunistic, devious and divisive. The Commons was told it was not right to “snipe” at the prime minister at such a dangerous time. The Times declared it “a great misfortune” for the country.

Brexit is not a decision about war and peace, life or death. But it is surely the most momentous issue that has faced parliament in more than 50 years. Once again there are voices telling us it is wrong to undermine a government and a prime minister caught up in difficult deliberations. Others tell us that we should not go against the referendum result — which they interpret as the British public’s settled will on every detail of the form of Brexit being prosecuted.

I do not accept either of these claims, but I particularly object to the latter. No one who sits in parliament, in either House, should see their job as being a weathervane driven by public opinion on each precise detail of Brexit (which is impossible to know) or as a rubber stamp for whatever a prime minister — this one a hostage of extreme elements in her party — decides on questions of the greatest national importance. Recommended Brexit Briefing Could Jeremy Corbyn back EEA membership.

My colleagues on the Labour benches in the Lords are used to being told that if they do anything that contradicts the government’s policy on Brexit they are flouting democracy. That claim was always false. A hard Brexit was not on the ballot paper in the 2016 referendum, but it was the central offer made to the electorate by Theresa May in last June’s general election. She lost her majority. As a result, her government is propped up by the DUP from whom, along with Jacob Rees-Mogg and his European Research Group of hardline Europhobes, she takes her orders.

However, this week it was Labour’s own leadership telling our peers to dance to the tune played by Mrs May and the Tory right. If it seems bizarre for Labour peers to be told that the wont of a Conservative government is the will of the people that is because it is indeed quite extraordinary. Rightly, Labour peers decided they had had enough of such timidity in the face of bad decisions by a bad government and supported amendments to keep Britain part of the European Economic Area.

Leaving the EEA would be a bad decision. Latterly, much of the debate in Britain has focused on the customs union. Yet in many ways the EEA matters even more because our economy is about 80 per cent services.

As a free-trade agreement that includes services, the EEA is massively important for Britain’s economic health and a significant contributing factor to our growing positive services trade balance. If that surplus starts to shrivel, the price will be paid not just by those who work in jobs that are at risk from lost trade, but by every household: for it helps pay for the food, the medicines, the cars and the fuel that we import every day.

And the burden would not be borne equally. Wealthy households can make decisions about discretionary spending that the less well off — especially the growing numbers of working poor — cannot. So it is unfathomable that Labour appears desperate to avoid voting against the government on the EEA when, given the growing number of Tory rebels supporting this cause, ministers face defeat on the EEA in the Commons.

The party’s leadership offers reasons, of course. The spectre of Leave voters in Labour areas in the north of England haunts the shadow cabinet. It is true that some potential Labour voters might value Brexit above the health service or prefer to eat chlorinated chicken than fight child poverty, but I hazard a guess the numbers are tiny. Smaller certainly than the numbers of former Tory and Lib Dem voters who would be attracted to a clear position.

Labour parliamentarians are also told we cannot vote for EEA membership because it would restrict a Labour government’s freedom to act to end economic inequality. But claims that the EEA would stop rail or water nationalisation, prevent the creation of regional investment banks or block more public housing are rubbish — all of these things exist across the countries inside the EEA.

I still hope the Labour front bench will swing behind the idea of negotiating to stay in the EEA. It would match our test, set last year, that any post-Brexit arrangement must give us the “exact same benefits” as now. Moreover, to win the vote would be to do incalculable damage to the plans of the Conservative hard right, who want to create a low tax, low regulation, free-market, free-for-all economy.

That might not be the sum of Labour’s present ambitions, but it would still be a noble achievement.

This article was first published in the Financial Times here.