'IN my view, he is the leader we have," said Peter Mandelson last week, damning Ed Miliband with faint praise.

Actually, he damned him with faint contempt as well, saying the Labour leader's policies were "confused and unconvincing". The arch Labour moderniser was adding his stiletto to the barbs being hurled at Miliband from all sides last week. Alan Johnson, the former Labour health minister, said he had to get over his "geek" image.

They're responding to the unmistakable message of the opinion polls: that Ed Miliband is unlikely to win the next General Election, despite Labour's marginal lead over the Tories. Six out of 10 voters, according to a YouGov poll in Prospect magazine, think Ed is not up to the job of Prime Minister. Ipsos/Mori in the Mail suggested that only 22% of voters think he can win. Nearly half of Labour supporters think he should go. This is not good.

A decent and thoughtful man, Ed ­Miliband has acquired an image of being a bumbling loser that will stick to him like a bad smell. Posing for a photo-op with The Sun and then apologising for it only compounded the image of haplessness. From now to the election, every local radio interviewer will be trying to make a name for him or herself by catching Miliband out on the cost of his shopping (like most professional people, he doesn't know) or on the names of obscure local politicians. Every would-be paparazzi will try to get photographs of him looking stupid while eating a bacon sandwich or whatever.

This is unfair. Ed helped Labour rediscover itself after the 2010 election defeat by drawing a line under the Blair years. Under Ed, Labour has adopted some genuinely radical policies - anenergy price freeze, breaking up the banks, raising the minimum wage, free childcare. The polling evidence suggests that most voters support these policies. Unfortunately, Ed lacks that indefinable quality of leadership and is lumbered with the back-story about "the wrong Miliband".

And now, the unreconstructed Blairite right of the Labour Party smells blood and is circling him like sharks after a weakened seal. Tony Blair's reappearance on the public stage, claiming that Iraq would have been worse without his invasion, has been the cue for them to regroup. Peter Mandelson and co believe Blair's right-wing policies remain the key to electoral success. They see a chance, in Ed's misfortune, of getting one of their own - or perhaps another right-winger like the shadow business secretary Chuka Umunna - to replace Ed after he loses the General Election next year. That'll get rid of all the social democratic nonsense and allow Labour to restore the prefix "New"; and revert to being Tory lite.

Unfortunately, Ed's response to this has not been to follow the arrow of principle, but to back-track and appease the right. Last week he announced that Labour would scrap automatic benefits for 18 to 21-year-olds, a pointless genuflection to the anti-welfare constituency that will fool no-one and, like his support for the arbitrary benefit cap, will only sow division in Labour's ranks. Neal Lawson, chairman of Compass, the left-leaning pressure group, says Labour "will never win on who kicks down hardest on the poorest". And he's right. This is Tory territory: leave it to them.

The same goes for Ed's concession of an in-out referendum on Europe "if Brussels demands more powers". It's only a matter of time before they do that, which means Labour has now boxed itself into an essentially Eurosceptic foreign policy.

I can't see this ending well for Ed. Time is running out to reassert his authority and paint over the Wallace and Gromit image. The economy is recovering faster than most thought possible and unemployment is falling too. Admittedly, this is on the back of an irresponsible credit splurge that will only deepen the debt problem of the UK economy post-May 2015. The Coalition's pre-election boom is a transparent contrivance, but it could be enough to destroy Ed Miliband in the General Election campaign. Those Ukip votes will go back to the Tories, not Labour.

So what does Ed's misfortune mean for us? Well, I'm not one of those who believe anything bad that happens to Labour is good for ­Scotland. The relentless rightward drift of Westminster is a bad thing for us all.

Every Labour politician on Question Time begins their remarks with the apology that they "got it wrong on immigration, benefits, the EU ... " They didn't. They got it right. Immigration is essential to address the problem of Britain's ageing population. Unemployment benefits in Britain are among the lowest in Europe. Leaving the EU would be economic and geo-political madness for the UK. Britain already has the kind of inequality and low pay of countries that used to be called the Third World.

Scotland is hitched to a ramshackle runaway train with Ukip stoking the boiler, George Osborne throwing the under-privileged off the carriage and Ed Miliband sitting in the guard's van wearing the wrong trousers. It won't end well. Scotland is regarded as an irritating irrelevance by Westminster, even by Labour politicians who resent this country for the fact that it still subscribes to the social democratic values they have abandoned. They want Scotland to hurry up and vote No so that they can enlist us into the "new right" consensus. "See - all that stuff about free education, open borders, unilateral nuclear disarmament, Nordic redistribution, green energy ... Scots have voted No haven't they? It's over." That's what they will say on September 19.

Scotland's referendum is a defining moment for UK social democracy, a make or break moment for a civilised society. It has fallen to Scots to make a decision that will resonate across the entire UK. Far from abandoning England to the mercies of neo-liberal Tories, a Yes vote will show that social democracy is still alive and well and living in North Britain. It will show that prejudice and xenophobia need not be the driving forces of politics; that the power of capital can be challenged and that countries can depart from the nuclear club.

A No will only accelerate Labour's rush to the right. The Tories will still win the General Election and inflict unprecedented austerity as they try to control the credit boom. There is an alternative: pull the communication cord on September 18 and decouple the train.