Ian Austin has really gone for the jugular with an attack on Jeremy Corbyn and the Labour left. Writing for PoliticsHome, the Dudley North MP accused the “hard left” of taking over the party, and said “mainstream social democrats” could not support Corbyn’s leadership.

It is without question the most explicit and personal attack on party leadership by a Labour MP since the 2017 election, but it is desperately short on any answer or suggestion of an alternative plan.

Austin does not mince his words. He offers up numerous criticisms, and expresses them with palpable fury; the list is so exhaustive as to essentially offer potted biographies of Corbyn and John McDonnell.

He writes:

It is ludicrous to pretend Jeremy Corbyn or John McDonnell would have supported a government led by Attlee and Bevin. The fact is that Labour has never in its history had a leadership as far to the left as this one. Never. And whilst Marxism has always been an important strand of thought for some in the party, previous Labour chancellors would never have said they were working to “overthrow capitalism” as John McDonnell did or when asked to name the “most significant” influences on his thought, reply: “The fundamental Marxist writers of Marx, Lenin and Trotsky, basically.” Jeremy’s supporters – for whom he can do no wrong – will dismiss this as the usual bitter smears to undermine him. But it is much more fundamental than that. The reason I didn’t support Jeremy’s candidacy and have not been persuaded since is because I just don’t think people with track records of extreme views like Jeremy Corbyn and John McDonnell should lead a mainstream party. No senior Labour figure would ever have backed violent street protest as John McDonnell did when as recently as between 2010 and 2012, he called for “insurrection” to “bring down” the government or praise rioters who had “kicked the s---” out of the Conservative Party’s offices in Westminster.

He goes on:

No previous Labour leader would have repeated Kremlin conspiracy theories when Russia was trying to kill people on the streets of the UK. No previous Labour leader would have defended a grotesque racist caricature or failed to deal properly with the anti-semitism crisis. No previous Labour leadership would have invited “friends” from Hamas and Hezbollah to an event in Parliament, praised as a “very honoured citizen” someone like Raed Salah who had been found by a British court judge to have used the anti-Semitic “blood libel”, or defended someone like Stephen Sizer, a vicar disciplined by the Church of England which said he spread ideas which were ‘clearly anti-Semitic’. And no previous Labour leader would have chaired the so-called Stop the War coalition which actually praised what it said was the “internationalism and solidarity” of ISIS, and compared it to the International Brigades, supported what it called the Iraqi “struggle” against British troops “by any means necessary”, said that it stood with Saddam Hussein, compared Assad to Churchill, and promoted or provided a platform for Assad apologists.

All of these are sentiments that Corbynsceptics can often be heard expressing privately, but rarely do they do so in so public a forum. On this evidence, they shouldn’t bother.

Austin ends his Jeremiad by concluding that the hard left have not only won control of Labour, they intend to change it into an entirely different party. “That's why mainstream social democrats do not support Jeremy Corbyn's leadership,” he concludes. And that's it. No mention of what those mainstream social democrats intend to do to stem the tide. No self-analysis.

Though intended as a devastating critique of the Labour left, there’s an argument to be made that Austin’s piece is in fact a harsher indictment on the political bankruptcy of the party's Never-Corbyn ultras. If the calamity is so great, where is the strategy to stop it? Trashing Corbyn alone, however justified the invective is believed to be, won't work. Ditto disparaging members supportive of the leadership as uncritical believers in Corbynite infallibility.

The idea that the road Corbynsceptics need to take if they are regain ground internally can be built by attacking those whose support will be needed to do so is, to put it lightly, pretty questionable.

But there is a much simpler point to be made here. Austin says above that his “fundamental” objection to the Corbyn project “is because I just don’t think people with track records of extreme views like Jeremy Corbyn and John McDonnell should lead a mainstream party”. If it's that fundamental – and the left are so entrenched and unstoppable – then why is he still in Labour?

The answer to that question, like so much else, is missing too. In the absence of a coherent strategy to win the party back, Corbynsceptics need to find a convincing one – and fast.