The Labour right are a puzzle. How come they are simultaneously so venomous towards Jeremy Corbyn and, as John McDonnell famously put it, so “useless”?

I’m not complaining that they’re nasty. The post war Labour government helped to create Nato and, as John Newsinger reminds us in the latest issue of the International Socialism journal, waged a series of vicious colonial wars.

During the 1950s and early 1960s the Labour Party apparatus conducted a ruthless campaign to crush the left, disbanding local parties and expelling individuals. In the 1990s the architects of New Labour turned the party into the humbled instrument of Tony Blair and Gordon Brown.

So the Labour right’s record is monstrous. But they were effective. They got things done, even if the things were often horrible. The present bunch are, by comparison, a shambles.

Look at the record. A plot rapidly discovered by Corbyn, who sacked the main culprit, Hilary Benn. Mass resignations by shadow ministers, which fail to force his resignation. Initially two “unity” candidates to challenge him, with arguably the weaker of the two staying in the race.

And all the complaints of “bullying”, whatever the truth to them, aren’t really a sign of strength.

So one explanation of the violence of the Labour right’s attacks is precisely that they are relatively weak.

The reform for which they campaigned for decades—electing the leader by one person, one vote—has tilted the balance of power towards a leftwards moving party membership. It gave Corbyn the legitimacy to defy the shadow cabinet resignations. Hence their impotent fury as they see “their” party slip away from them.

The last time the Labour left advanced, in the late 1970s and early 1980s, the right split. Some, like Denis Healey and Roy Hattersley, stayed and fought. Others broke away. But that kept the Tories in office for 18 years.

This makes splitting to create a new “centre party” today an unattractive prospect. Moreover, the Lib Dems, the remnant of the last split, are hardly a very attractive partner. And Theresa May is trying to move the Tories onto the centre ground to occupy the space a new party could supposedly seize.

Vacuum

But there’s also an ideological vacuum. New Labour was about reconciling neoliberalism and social democracy. It was Brown who as chancellor tried to turn this idea into policy substance. He gave the City “light-touch” regulation in the hope that it would generate enough tax revenues for modest redistribution mainly via means-tested benefits.

Two failures destroyed New Labour. The first was Iraq, of course. The second was the financial crash, which destroyed this devil’s pact with the City. It also brought to office David Cameron and George Osborne, who slashed the benefits Brown had introduced.

The New Labour retreads who dominated Corbyn’s shadow cabinet till last month despised Ed Miliband for inching the party leftwards and campaigning for “responsible capitalism”—a slogan that, ironically, May has now pinched.

But what’s their alternative? What do they stand for? Hilary Benn’s ridiculous tub-thumping speech last December portraying bombing Syria as an anti-fascist struggle looks particularly hollow after the Chilcot report. And, at a time when the Tories are promising a “reset” in economic policy, Owen Smith talks about continuing austerity.

So the Labour right have seen their power in the party drain away, and haven’t an idea to their name.

Their only real weapon is to split Labour, which will probably mean their own eclipse. I think we’re already seeing the beginnings of a slow-motion breakaway, as increasingly the Parliamentary Labour Party starts operating independently of the rest of the party.

To counter this, Corbyn and his allies will need to do more than merely win the leadership election.

They will have to make a reality of their promise to turn Labour into a “social movement”. This will mean participating in campaigns against racism and austerity. It will mean building solidarity with strikes.

And it will mean developing a set of alternative policies to those of the Tories and to the hollow shell of New Labour in the House of Commons.