Tony Blair's endorsement of Ed Miliband should bode well for Labour's election chances

Is it a help or a hindrance to have Tony Blair endorse your election campaign? It seems odd that the question should even have to be put, given that Mr Blair was the most effective vote-winner the Labour Party ever had.

But in February, the polling company YouGov asked whether having Tony Blair intervene in the election would be an “asset or a liability” for Ed Miliband. Taking the percentage of voters who said “asset” and subtracting the percentage who said “liability” gave Mr Blair an overall score of minus 47, the worst score for any of the retired politicians road-tested by that polling company. Even among Labour supporters, he scored minus 22. That may explain why Mr Miliband chose to go to Bristol today, rather than be in the audience in Mr Blair’s old stomping ground in Sedgefield, Co Durham.

But the findings of surveys and polls have to be treated carefully. Yes, there is a vociferous element of the population that retains a particular loathing for Tony Blair, as both the man who took the UK into the Iraq war and – as this element would have it – the man whose New Labour project was a betrayal of “Old Labour”. The inescapable truth is that Mr Blair was voted into Downing Street in three successive general elections, the third of which was a full two years after his catastrophic misjudgement over Iraq. Still that was not enough to deny him another stint in No 10.

Mr Blair’s “unhelpfulness” to Labour – the extent to which he has become a liability to the party – means that any intervention he makes in domestic politics is pored over for hidden meanings. It would have been understandable if he had chosen to stay right out of this election campaign. Instead, he sought to banish the perception that his support for Ed Miliband was less than total by declaring that he was 100 per cent behind him, while taking the fight to David Cameron by attacking the Prime Minister’s pledge to hold a referendum on Britain’s EU membership. It would, Mr Blair said, cause economic chaos.

There are those who think that merely by putting the case for not holding a referendum, Mr Blair was doing Labour no favours. That’s because, when asked, people will usually say that they are in favour of referendums as a general principle, and there is a passionate minority who believe we should withdraw from the EU. But it was to Mr Blair’s credit that he raised this subject, in an election in which the main parties seem to be incapable of talking about anything but tax, austerity and the health service. At least he changed the agenda, and he presented a clear, coherent argument in which he was obviously driven by conviction rather than the need to bid for votes. There was none of the “I’m a straight sort of guy” talk which worked for him early in his premiership, before people saw him as another professional politician dealing in the half-truths and evasions that are the stuff of politics. He did well to remind people who are in favour of referendums in the abstract that they can come at a very real cost.

He also sprang a surprise in the question-and-answer session that followed his speech, when he said that he agreed “completely” with what Mr Miliband has been saying about inequality. This was not something we remember him being passionate about during his 10 years in office, but it reinforces the point that concern for inequality is mainstream Labour Party thinking, not some foible of Mr Miliband’s.

The current Labour leader’s strength has been his ability to hold Labour’s core support together after the defeat of 2010. Now he badly needs to reach out beyond that base to the uncommitted. No one in living memory has done that more successfully than Tony Blair. For all the justified criticism levelled at the former Prime Minister, Ed Miliband had good reason to be pleased to see him back in action, and fully onside.