The “Stop Jeremy Corbyn” campaign has gone into overdrive in recent days.

The left-wing candidate for Labour Party leader has come under a barrage of hostile and even defamatory criticism.

Everything about him, from his choice of headgear to his age and gender, has come under attack — except for his policies.

Media pundits and political opponents have loudly proclaimed his unelectability.

Former Blairite health minister Alan Milburn, now employed by privatisation facilitators PriceWaterhouseCooper in its healthcare sector, claims that a victorious Corbyn would “lead the Labour Party to oblivion.”

Yet many of the Labour frontrunner’s cornerstone policies are widely popular.

Every public opinion poll indicates that substantial sections of the British public are opposed to austerity, privatisation and renewing the Trident nuclear weapons system, while a majority support the redistribution of wealth and public ownership of the railways and energy utilities.

And, if we must get personal, the Islington North MP has increased Labour’s share of the vote in his own constituency from 40 per cent in 1983 to 60 per cent last May.

Milburn’s share went in the opposite direction before he quit Westminster to spend more time with his wallet.

A common accusation made against Corbyn is that he and his supporters prefer ideological purity and electoral defeat to “sensible” and “moderate” (for which read pro-austerity, pro-Trident, pro-big business) policies and the election of a Labour government in 2020.

His accusers even shed crocodile tears for the plight of the poor and disabled who will desperately need respite from the very Tory welfare reforms that most Labour MPs refused to vote against last week.

At the same time, there has been no condemnation of ex-leader Tony Blair’s declaration to the right-wing Progress group that he would rather lose an election than win it on an “old-fashioned leftist platform.”

Corbyn’s campaign indicates that radical left-of-centre policies, put forward in an informed and reasonable way, might enthuse many of the five million people who on May 7 voted Green, SNP or Ukip for the first time.

These electors are a better target for Labour’s vote-winning efforts than the 600,000 extra Tory voters.

Indeed, Labour’s appeal would be all the stronger in most of these constituencies if it adopted a more sceptical approach to Britain’s membership of the pro-austerity, pro-privatisation and anti-trade union European Union.

The lowest note in the “Stop Corbyn” campaign so far was struck by Labour MP John Mann last Thursday.

In an “open letter,” he accused his parliamentary colleague of assisting in the “cover-up” of child sex abuse allegations in Islington, albeit “inadvertently, impelled by the ‘trendy left politics of the 1980s’.”

The charge was easily refuted by pointing to the accused’s long-time record and by completing Mann’s partial quotations.

In making it, the Bassetlaw MP demeaned himself and did a grave disservice to the hard work he himself has done to expose child abuse.

Now Mann has led a charge to have the Labour leadership contest called off, because “Militant Tendency types” have infiltrated the party in order to outvote loyal members and elect Corbyn.

The Murdoch-owned media have indicted Greens, the SWP and — mistaking an insignificant sect for the real thing — the Communist Party for the same offence.

It is to the credit of Labour leadership candidates that they have dismissed such anti-democratic, anti-Labour froth.

Greater concentration on policy debate will win the party more members and, given the best result, winnable policies.