EVERY summer since Jeremy Corbyn became leader of the Labour Party has seen a campaign to bring him down.

In 2016 the “chicken coup” saw a challenge to Corbyn’s leadership that took the heat off the Tories following David Cameron’s resignation.

Last year a largely artificial row over allegations that the leadership is tolerant of anti-semitism had Margaret Hodge win headlines with foul-mouthed smears on Corbyn in Parliament and succeeded in bullying Labour’s NEC into adopting a definition of anti-semitism rejected by its own author for conflating racism with political criticism of Israel.

Even 2017, the election year, saw disloyal MPs attacking the leader throughout the campaign, though most were silenced by the party’s strong performance in the vote itself.

The smear season has begun again and Labour is right to warn that this week’s Panorama drama on whether the party is anti-semitic will be a partisan hatchet job based on interviews with Corbyn’s political enemies.

It airs a day after a meeting of the party’s national executive is expected to discuss two highly charged issues: whether to reopen an investigation into suspended MP Chris Williamson following a tantrum by MPs and activists who disagree with the original panel’s decision and whether to adopt the pro-Remain line being pushed by deputy leader Tom Watson rather than maintain its commitment to delivering on the 2016 vote to leave the EU.

Attack lines come thick and fast, with Sunday Times allegations that shadow cabinet allies of Corbyn have turned on his advisers following public lobbying by journalist Paul Mason that he fire them.

Shadow international trade secretary Barry Gardiner chides media organisations for obsessing over Labour divisions when the real dividing line in Britain is between the government of the richest and the rest of us.

However, even if shadow cabinet members have an obligation to emphasise unity, the wider left has a duty to recognise that the richest-versus-the-rest divide runs through the Labour Party as well.

The constant public pressure on Corbyn is aimed at weakening him and defeating the left. This is true of accusations that he is anti-semitic when his record of campaigning against anti-semitism puts that of most MPs to shame.

It is true of demands that he intervene against Williamson, another MP with a decades-long record of anti-fascist activity whose reputation is being shredded in the media by unscrupulous liars. It is true of demands that he fire loyal aides and of public attacks on him over the party’s line on Brexit.

The left has to be bolder in fighting back. Attempts to respond to political attacks by referring questions to supposedly neutral bodies cannot work when Corbyn’s enemies won’t play by the rules.

Labour’s warning that Panorama’s “investigation” will be nothing of the kind is a welcome indication that it is wise to the BBC’s disgraceful record of attacks on its leader and constant amplification of his opponents — and to the fact that expecting impartiality from any part of the British state is dangerously naive.

While all politics involves compromise, such deals should be struck with potential allies and designed to advance the socialist cause. Concessions to figures whose goal is nothing less than the destruction of the Corbyn project are damaging and demoralising.

The great labour movement festivals of the Durham Miners’ Gala and the Tolpuddle Martyrs should be a roar of defiance at the Establishment’s bid to crush the most impressive socialist movement anywhere in the developed world.

The summer of campaigning against Tory racism, Tory cuts and the Tories’ rigged economy that Corbyn has called for should be aimed at building irresistible pressure for an election rather than the coronation of a new Tory PM, and building a movement that can win that election and implement the radical and needed reforms that only Labour is promising.