The proposed vote of no-confidence in Jeremy Corbyn worries me: I fear it is based in part upon three motives that are wrong, one of which is plain vicious.

The first of these wrong motives is that Mr Corbyn was only half-hearted in campaigning for Remain. In fact, his giving the EU a seven out of ten was a rare light of honesty in a campaign dominated by lies and exaggerations. The EU's treatment of Greece, and its tolerance of mass unemployment testify to the organization's flaws: Andrew Lilico is right to say it must be reformed radically.

The second motive - expressed by Frank Field on the Today programme - is that Mr Corbyn in not a "credible" Prime Minister. He says: "We clearly need somebody who the public think of as an alternative prime minister."

Now, this statement comes at a time when Boris Johnson is odds-on favourite to be next Prime Minister. The fact that a liar, charlatan and hypocrite can be regarded as a plausible PM shows that our political culture - fostered by the BBC - is deeply sick. Labour should be fighting this, not acting as Quislings for a feudalistic deference to the high-born.

My biggest problem, however, is that I fear that the desire to get rid of Corbyn is based in part upon a desire to "listen" to "concerns" about immigration - expressed by Mr Field this morning. As one rentagob put it*:

Labour has gone wrong by not being in touch with its voters. I've been saying this for the last 10 years in relation to immigration and free movement of labour.

This, of course, misses the facts. Immigration is not responsible for low wages, job insecurity and the difficulty of seeing a GP. Mr Corbyn is wholly correct to say that a large part of the solution to this is to have "an alternative to austerity**."

It could be that those who want to shift Labour towards greater hostility to immigrants want to use the Farage-Hannan trick of winning elections: lie your face off during the campaign and then disown your promises after you've won. This, however, is risky. For one thing, there's a danger of getting high on our supply - of believing your own lies. And for another anti-immigration talk has real consequences: it stokes up hate and makes immigrants (and let's be honest, British-born ethnic minorities too) less safe on the streets. That is utterly intolerable.

Now, I'll concede that there might well be more reasonable motives for wanting Corbyn out: I've no beef with Nick's complaints about his curious associates, and I fear there's some merit in the allegations that his organization and campaigning skills are weak.

In throwing out this bathwater, however, Labour risks losing a beautiful baby. John McDonnell is building one of the best economic platforms a major political party has had in my lifetime. It would be a tragedy if this is lost in a retreat towards reaction and economic illiteracy.

* Insofar as this is a motive for hostility to Corbyn, it is wholly wrong to present the issue as one of Blairites versus the Left. For all their flaws, Blairites were - to their credit - not anti-immigrant.

** I'd add that this alternative should be at a pan-European level; a big reason why immigration is so high is that one-in-five under-25s in the euro area is out of work (pdf). Sadly, however, the UK has lost much of its influence to make this argument.