There is a story about Jim Murphy being out with his campaign team in Eastwood in April 1997 and being stopped by the police. When he explained he was the Labour candidate the officers told him he was assured of their vote, and a friend broke the astounding news to him that this meant he was about to win the Tories' safest Scottish seat.

Mr Murphy was said to have become the accidental MP, but more than a decade later his elevation to Secretary of State for Scotland is anything but accidental. We can call him a Scottish Mandelson and no offence will be taken.

Mr Murphy had a decent start to his new post, showing that he had learned some of the lessons of the past and demonstrating that if he is to win arguments with the Salmond administration, he must do so at the right tangent.

He has been put into Dover House to arrest the Labour slide in Scotland. Glasgow East was an alarm call, he may be too late to save Glenrothes, and Motherwell and Wishaw has been finessed by a most peculiar exercise of prime ministerial patronage.

But Gordon Brown's concern is shoring up Labour seats across the country at the next General Election, so who better to pick than a candidate who will be fighting for his own political survival in East Renfrewshire?

If Mr Murphy can pull off collectively across Scotland at the next election what he achieved and built on in his own constituency, then Labour will have some hope of avoiding a terrible drubbing.

Is saving Labour from that a realistic prospect? Let's examine the likelihood. It would be fair to say Mr Murphy has always been a phenomenal fighter for his wing of the party, attracting an Early Day Motion by Ken Livingstone and other lefties on student debt condemning his "intolerant and dictatorial behaviour of the President of the National Union of Students", at a time when he persuaded the NUS to begin accepting Labour's assault on student finances.

The Commons attack said: "While these methods are a common practice in dictatorships around the world, they are not acceptable behaviour from someone such as Mr Murphy who is putting himself forward as suitable for election to the House of Commons." In fact, behind all Comrade Livingstone's hot air, what they were complaining about was Mr Murphy's ability to lead and organise. Ken's Reds could rail all they liked. Mr Murphy was part of a changing landscape called New Labour and what the old left really hated was the effectiveness of their enemies. When potential Labour candidates for Holyrood were being assessed, the Blairite Network organisation set the height of the bar. When Messrs Murphy and Mandelson found themselves at the heart of Tony Blair's government it was as front-line veterans of the Clause Four wars.

Mr Murphy stressed at the weekend that he would meet with Mr Salmond, describing the Holyrood administration as the Scottish Government, rather than executive, and work with him on clear areas of Scottish interest. This marked an important start for Mr Murphy, given the Dover House aides who sneered at this terminology.

Mr Murphy backed the idea of more lottery cash for Glasgow and, by extension, would seem open to the arguments about London East End regeneration money that should be diverted back to Glasgow's East End. He was up for backing Team Salmond on big campaigns for Scottish jobs in the current financial crisis.

But his two firm areas of objection must be addressed. Does he believe that council tax benefit should be retained by Westminster no matter the reform made in Edinburgh? That smacks of an argument that Scots can only reform council tax, a devolved issue, if the plan is approved by the Treasury. If I were Mr Murphy I would escape from that argument sharpish.

Indeed, there is a compelling argument for giving Mr Salmond his council tax benefit money precisely to allow the whole system to fail, so that if the scheme does fail no blame attaches to Westminster.

And on the referendum question, does he not recognise the Salmond claim that his referendum model was consciously modelled on that of Donald Dewar? A decision in principle, followed by practical detail? If that is a rigged referendum, say the Nationalists, so was the devolution poll.

Politically, Mr Murphy will have to find a balance between taking on Mr Salmond and sidestepping him. He will not win by taking him head-on because he will be confronting an essentially popular politician with a perceived democratic mandate.

Mr Murphy will have to weigh up how to tackle the SNP across the country, while within his own political tribe having to face the Tories in his own back yard.

The new, more mature Jim Murphy may be up to these challenges. His performances over the weekend show he knows some of the dangers. If Labour is to have hope he has to respect Scottish democratic opinion, no matter how much he resents the result of that process last year.