Let's get one thing straight.

Labour MP Jim Murphy is an immensely capable politician - industrious, combative and intelligent; a natural campaigner who turned the referendum into what was almost his own presidential campaign, with his 100-town tour on an Irn-Bru crate.

He has the ideal back story: a Glaswegian; slept in a drawer when he was little because his family was too poor to afford a bed; even wrote a book about football. The press can't get enough of him. He is a former Scottish Secretary, a former UK Cabinet minister, the best "striker" Labour have and a politician with the potential to transform First Minister's questions. He is also a teetotaller and vegetarian.

Labour would be mad not to let him stand for Scottish party leader if he wants the job. Unfortunately, Labour would also be mad to give it to him. Their tragedy is that they almost certainly will. Jim Murphy is an offer the Scottish Labour Party cannot refuse.

But, as the former Labour minister, Malcolm Chisholm, has pointed out, putting a Westminster MP in charge of the Scottish party in its present fragile state would "turn a crisis into a catastrophe".

This is not because because Scottish MPs cannot lead Scottish parties; of course they can, as Alex Salmond demonstrated between 2004 and 2007. But Jim Murphy would be seen inevitably as London Labour's man in Scotland. He might even install someone agreeable such as Kezia Dugdale as his stand-in at FMQs but they would be not be able to speak their minds.

The trouble with Mr Murphy is that he stands for all the wrong things to lead the fight against the SNP. He was rejected by Ed Miliband for one of the big-four shadow Cabinet posts not because he isn't capable, but because he is a dyed-in-the-soul supporter of Tony Blair, a true believer; what Labour people used to call a "moderniser".

He was an enthusiastic supporter of the Iraq war and did not go along with Ed Miliband's mumbled apologies for the invasion. He is committed to nuclear weapons in a way that very few Labour politicians are. He voted for the return of university tuition fees and ID cards and supports market reforms in the NHS.

Now, he is quite capable of putting this all into the background, and adopting some quite left-wing policies in Scotland, perhaps even cheap childcare.

He knows how to appeal to the social democratic sentiment of his party by picking up issues such as housing and land reform. He will launch tabloid campaigns against noisy neighbours, rowdy classrooms and hospital cuts.

However, top of his agenda will be to close down the party as an autonomous force in Scotland. He will have to do this because, from his point of view, there is no alternative.

Labour can only win in Westminster, as Mr Murphy has said himself, if it wins in the south. It cannot allow itself to be dragged to the left by an "old Labour" enclave in Scotland.

This is why Johann Lamont wasn't allowed to break with party policy on the bedroom tax; why the plans for tax devolution were over-ruled; why the Scottish party has been kept in its place as a "branch office". Labour remain a centralist party and the history of devolution has all been about how it has failed to resolve its own north-south divide.

There is civil war raging in the Scottish Labour Party. Former Labour First Ministers, including Jack McConnell, have used Johann Lamont's departure to settle their own scores with London Labour.

Andy Kerr, Labour's former finance minister, has said that Labour delivered the Scottish Parliament and then "tried to strangle it at birth". He said he felt sorry for dinosaurs being compared with Scottish Labour MPs.

This can't go on. Jim Murphy will be brought in to end it once and for all. He will talk up the supposed constitutional autonomy of Scottish Labour, but he will weld it organisationally to the UK party where the true power lies. And, in the long term, that can only hand Scotland to the SNP.

But for now he is unstoppable. He is the One, the Neo. Defective Labour programmes will be deleted.