THERE should be no illusions about previous Labour governments. For the most part they have served the interests of the ruling capitalist monopolies, even when they were making concessions to popular concerns.

All were led by right-wing leaders who justified their betrayal of promise and principle with social-democratic notions such as the neutral state, nation rather than class and “benign” imperialism.

But what about Attlee’s much-vaunted government of 1945? It was the worst of the lot. How dare I make such a charge? Because, unlike other Labour governments, it had a real opportunity to change the world for the better — and didn’t even try.

1945 was a unique year. For the first time the British people had voted for fundamental change. All over the world the victory over fascism had inspired movements to win a people’s peace — but greatly strengthened US imperialism stood in the way of global progress.

Instead of working with all the potentially progressive forces, including the American people, to end colonialism and move towards socialism, the Labour government — flouting its own manifesto — signed up to the US cold war against the Soviet Union.

The ensuing calamity can be revealed in three key dates. On July 5 1948 the NHS was launched, almost certainly the best thing any British government has ever done; less than a year later, on April 4 1949, Britain was a founder member of US imperialism’s Nato alliance, arguably the worst thing any government has done; and two years later, on April 23 1951, Aneurin Bevan, creator of the NHS, resigned from the government because it had imposed charges for some NHS services.

This was a direct result of joining Nato and being forced to increase military spending.

Later the “special relationship” with the US would result in US corporations profiting from more and more NHS services. Establishing Nato was a key incident in a process that led to membership of the EU, to wage freezes and witch hunts, and to many years of Tory government. That is the legacy of Labour in power.

But condemning past Labour governments does not mean writing off the Labour Party as the political agency for advancing the interests of the working class and the vast majority of the British people.

Four years of Corbyn’s leadership demonstrated two important truths.

First, the reaction of the powers that be showed how vulnerable the ruling capitalist class is. The mere threat of a left government was enough to unite the whole of the Establishment and the mainstream media in using every weapon they could devise to undermine the Corbyn project. This was proof of the potential power of a united working class.

Second, the 2017 election shattered the myth that British people would never vote for a left leader with a radical manifesto. The most consistently left leader the party has ever had, committed to working for fundamental change, secured the biggest election-to-election increase in the Labour vote since 1945.

The ruling class used its remaining strength to get rid of Corbyn and impose the most right-wing leader Labour has ever had. But its underlying weakness was revealed.

There’s good reason to hope that a new effort to reclaim Labour for the working class will meet with eventual success, especially if the movement learns from the weaknesses of the Corbyn years.

The unions founded the Labour Party, they fund it, and they have the power to determine its policies and elect its leader. Today union militancy in struggles to raise wages, protect conditions, and restore public services is rising to levels not seen for more than a generation.

Strikes and the threat of strikes are winning victories. So much so that the Tories are threatening to introduce even tighter restrictions on trade union freedom of action.

The unions will have to launch a political campaign against the Tory government. It will be an opportunity for trade union activists at national, regional and local levels to engage with the Labour Party.

They will have the chance to profoundly influence the party’s policies and actions, not just on trade union law but on all the other issues arising from a deepening capitalist crisis: cost-of-living, public services, climate change, threat of war and the rest.

In this way the British people might reap the benefits of their unique advantage in having a single trade union centre linked to a single major political party representing the vast majority of workers.