“WHEESHT for Indy”. This is the code used on social media by SNP folk attempting to silence comment on the party's manifold internal crises. Don't rock the boat, they say. Wait until after independence. Look at the bigger picture. Well, yesterday an even bigger picture dwarfed the independence campaign, and the boat has sunk with all hands.

The sacking of one of the SNP's most capable and intelligent MPs, Joanna Cherry QC, from her post as justice and home affairs spokesperson is one of those epic moments in politics. It's as if Tony Blair had sacked Gordon Brown in 1997. It has brought to a head three divisions which have shattered the unity of the Scottish National Party: the Salmond affair, the transphobia row and the lack of progress toward independence.

Ms Cherry had called for Alex Salmond to be readmitted to the party after he was acquitted of all sex harassment charges last year. This did not endear her to the party leader. Next week, Mr Salmond is scheduled to give evidence to the Holyrood inquiry investigating how the Government came to lose a total of £692,000 fighting a doomed defence against his judicial review in 2019. There has been a clearing of the decks in advance of this appearance, in which the former leader is expected to blow open the conspiracy he claims led to his downfall.

Read more: The jury found him innocent but Alex Salmond is still on trial

Ms Cherry has also been an inconveniently outspoken supporter of women's rights. Indeed, she may be the first senior politician to be sacked for believing that a woman is an adult human female. She is a lesbian and a feminist who does not accept that women's sex-based rights should be sacrificed on the alter of an ideology which denies that sex is binary. In short, she does not believe “transwomen ARE women”. For months, Ms Cherry has been the target of vilification, abuse and even death threats from numerous trans activists in and out of the party.

This is such an arcane issue, baffling to the vast majority of Scottish voters, that it seems hard to believe it could have come to this. But Nicola Sturgeon has staked her reputation on driving through a new Gender Recognition Act which will allow men to self-identify, legally, as women merely by making a declaration to that effect. Last week the First Minister made a thinly-veiled attack on Ms Cherry in a video accusing her own party of transphobia. Yesterday, amendments to the much-criticised Hate Crime Bill that would have protected “gender-critical” women like Ms Cherry from prosecution for “stirring up hatred” were suddenly withdrawn by the Justice Secretary, Humza Yousaf.

The key amendment gave freedom of speech protection to “discussion, criticism or rejection of concepts or beliefs relating to transgender identity”. It also protected “stating that there are only two sexes” and using the words “man” and “woman” to define a person's sex. The deletion of these amendments could mean that women who object to the presence of natal men in their changing rooms, or in women's sporting events, may in future be committing a criminal offence.

The SNP NEC has been trying to enforce a new definition of transphobia in which even the phrase “adult human female” would itself be regarded as hate speech. However, it is also the dictionary definition of a woman, and if quoting it is to be regarded as transphobia then there might have to be a bonfire of biology textbooks. Universities could have trouble teaching medical students about binary human reproduction.

Read more: Don't tell women what makes a woman: they were born that way

Ms Cherry is an experienced advocate and the best legal mind in the SNP. She took Boris Johnson to the Supreme Court in 2019 over his prorogation of Parliament and won. In recent months she had been advocating a legal route to independence through court action on Indyref2. This is a route which Ms Sturgeon has reportedly endorsed herself. So it might seem perverse to dispense with the services of the only figure in the party with the legal expertise to prosecute it. But in the SNP right now legal expertise appears to be regarded as a threat.

These issues have been boiling and roiling beneath the surface of SNP politics for the last two years. The waves of scandal have been lapping around Ms Sturgeon's ankles as she tries to deal with the pandemic. Now, rather like Chairman Mao in 1966, she has decided to deal with troublesome opposition by launching a purge, and giving a green light to trans activists in her youth wing, who are highly organised on social media.

There is a generational divide in the SNP. Many younger nationalists are zealous advocates of identity politics. Older, analogue politicians, like the former Justice Secretary, Kenny MacAskill tend to side with Mr Salmond and Ms Cherry. The influential Wings Over Scotland blog, penned by the Rev Stuart Campbell, which was essential reading for independence supporters in 2014, is now calling for the resignation of Ms Sturgeon and the “woke” legions who are her new praetorian guard.

Wings has been assisting the former British diplomat, Craig Murray, in his attempts to disclose details of the alleged conspiracy against Mr Salmond. Mr Murray is in turn defending himself against contempt of court charges relating to the Salmond trial. Another prolific SNP blogger, James Kelly of Scotland Goes Pop, has called on Mr Salmond to launch a new independence party.

Struart Campbell, Wing Over Scotland blogger

Struart Campbell, Wing Over Scotland blogger

Like most SNP intellectuals, Mr Kelly had been arguing that it would be senseless to promote division on the eve of a crucial election which could trigger independence. The SNP lead in the polls indicates a landslide in May. However, he now believes the situation is so dire that the two wings – no pun intended – can no longer coexist.

The truth is that many in the party no longer believe that Ms Sturgeon is serious about delivering independence – at least not in any timescale they would regard as acceptable. Thousands have reportedly left in disgust. Ms Sturgeon dominates Scottish opinion polls and the opposition parties are disarray. Her biggest political threat now comes from within her own party.

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