Labour leadership fears that an avalanche of MPs will follow Frank Field in resigning the party whip

The antisemitism row, far from abating, has suddenly escalated to dangerous proportions.

Frank Field, who insists he is not a gesture politician, shocked the leadership by his decision to resign the party whip over the issue, and because of alleged intimidation within the movement.

The leadership have been fearful that Field’s action would be followed by an avalanche of his fellow MPs following suit, which would thrust Labour into as bad a crisis situation as it has experienced in its entire lifetime.

More and more Labour MPs are expressing concern at their leader Jeremy Corbyn’s stance on antisemitism. But resignation is a huge step for an MP to take - it would blight his/her prospects of being able to fight the next general election.

Meanwhile, Jonathan Sacks, the former Chief Rabbi, has renewed his attack on Corbyn, saying his stance is at least as bad as that taken by Enoch Powell - that remark must have stung Corbyn more than anything. And former Prime Minister, Gordon Brown has waded in, saying this issue is destroying the soul of the Labour Party and must be resolved - quickly.

Adding to this, the hard-left campaign group Momentum, much-feared by moderates, is calling for a change in the system of choosing parliamentary Labour candidates. This is seen as a sinister move designed to dump anyone who is not a hard-liner.

Altogether, a sorry mess which, far from being cleared up, is getting worse every day.

• Sir Vince Cable appears to be playing a tantalising game of cat and mouse with his own political future, and that of the scarcely visible Liberal Democrat Party he leads.

He has insisted he is not resigning early from the leadership, but says he will lead the party into the next general election if it is called “in the near future”, which certainly implies he does not expect to retain his post if this Parliament runs its full term to 2022.

Sir Vince has also been hinting that the Liberal Democrats may consider the prospect of having a leader who is not a Member of Parliament. That may become inevitable if the Liberal Democrats’ scanty numbers in the Commons are reduced much further. For a man who says “I’m certainly not stepping down”, he seems strangely obsessed with the leadership issue.

There has also been widespread speculation he’s been involved in secret meetings in what used to be called smoke-filled rooms with some shadowy political figures considering the question of the formation of a new left-of-centre party, which would presumably include those moderate Labour MPs who are considering defecting.

Sir Vince is planning to deliver what might be called a major pre-conference speech in a few days’ time, during which he aims to clarify the murky situation and offer a few clear answers to the questions he has posed.

But, don’t be too sure. A politician’s idea of clearing up a mess, is often to make it worse. And that could mean the Liberal Democrats facing a lingering death.

• Alex Salmond, the former First Minister of Scotland, has come under attack for launching a crowd-funding operation to enable him to finance a legal challenge to the Scottish Government over accusations of sexual harassment against him.

But I believe that Salmond, who fiercely denies these accusations, is quite within order in taking this action.

After all, those who are investigating these allegations are presumably using taxpayers’ money to do so.

If what he says is confirmed, Salmond has been shamefully treated over this affair. He has apparently been kept in the dark about what has been going on. He does not even know who those who have complained about his alleged conduct are.

Anyone whose reputation is at stake and who is facing such serious allegations, is entitled to be aware of what is going on.

To pursue this issue behind his back, so to speak, is outrageous.

• Sir Vince Cable is probably the last person the Prime Minister would want to take lectures from. But if she wants to improve her dancing technique, she may have to.

Cable is, in fact, a smooth and accomplished performer on the dance floor. He has even appeared on Strictly Come Dancing, although not as a contestant. You could say he is the Fred Astaire of Westminster.

But if the Liberal Democrat leader is Fred Astaire, Theresa May is certainly not Ginger Rogers.

Her galumphing “style” was visible for all to see - not once but twice - during her three-day trip to Africa. One day, perhaps, when she has more time on her hands, she might be invited on to the show as the natural successor to John Sergeant and Ann Widdecombe two of the great but unintended comics of the light fantastic.