John Rentoul: Ghost of PM past cannot be silenced

As a familiar figure returns to our media, Brown's and Cameron's success depends on how they build on public service reforms

Amournful document was added to the piles outside the Press Gallery of the House of Commons last week. Life After Losing or Leaving is a report for the Association of Former Members of Parliament by the University of Leeds. It paints a sad picture of ex-MPs, often bruised by election defeat and struggling to adjust to being a non-person whose phone rarely rings. "Don't expect any help or interest from your party," said one of those surveyed. "You are very much on your own." No, it wasn't Tony Blair. But it could have been.

All summer, the silence of the Labour Party about its former leader was ear-piercing. His name was barely mentioned at annual conference in Bournemouth – and when it was, delegates did not know whether to stand and cheer, clap politely or pretend they had not heard. They generally opted for a compromise between the last two. In Westminster, MPs and journalists shared their wonderment at the way the hyperactive personality that had been so dominant for 13 years had dropped out of sight so suddenly. And while Gordon Brown in his honeymoon cups posed as Margaret Thatcher's prodigal son, they shook their heads at David Cameron's naive error in claiming to be the heir to the leader of whom the nation had tired so quickly.

Then the spell was broken. Brown could do nothing right and Cameron – seemingly on the basis of a single speech, again, even if there was more to it both times – had regained the advantage. And there was the familiar voice on the radio, warning the world of complacency about Iran's nuclear ambitions. His name was canvassed as EU president – it wasn't a new story, but because Nicolas Sarkozy, the French president, was doing it, Brown was asked about it and forced to say what a terrific idea it would be. That it was an old story just added to the sense that Blair had never been away.

Last weekend, his tiffs with Gordon were in the newspapers. It all sounded so familiar: the screaming matches, the abuse, the petulance on both sides. Familiar too in the sense that we were none the wiser as to what any of the arguments were about. Last week, Blair sold his memoirs, which he has not started writing and which I predict will not be published for many years. The true story of the Blair-Brown relationship, as ever, will have to wait.

Meanwhile, Charles Falconer was on the telly, defending Blair's achievements against a sceptical BBC Question Time audience. It was as if nothing had changed. Except for the speech Blair gave in Calgary, Canada, on Friday: a £180-a-head sell-out event to hear the familiar – to us – combination of global apocalypticism and light humour. He told them he had seen a local newspaper headline, "Premier under fire", and thought: "What have I done now?"

And, before you can say "back-seat driver", David Aaronovitch will present a big BBC1 retrospective next month based on long interviews with Blair.

Brown ought to be satisfied with this return to normality after the unreality that prevailed over the summer. Pretending Blair never existed was not a plausible posture: he was always going to have to sell himself as someone who would learn from the mistakes of the Blair years while building on the successes. That is why Brown's excuse for not having an election now – that he needed time to set out his "vision" – was so inept. His vision is no different from the modernised social democracy that has carried all before it for more than a decade.

If Leeds University had taken Blair as a case study for its report on life after the House of Commons, it would have noticed not so much his gradual return to our headlines and broadcast media, but the persistence of Blairism. How Brown and Cameron position themselves in relation to Blair's legacy of public service reform is going to decide the struggle between now and the next election.

This is the more interesting story of what is going on at Prime Minister's Questions than the unsurprising revelation that Brown is not a quicksilver-debater like his predecessor. For two weeks now, Brown has defended the use of targets in the NHS. Targets in health and education – and the increasing use of new providers to achieve them – are the Blair reforms that worked best. It is because of them, as Brown reminded the Commons last week, that by some time next year no one should wait longer than 18 weeks for NHS treatment.

Of course, many public servants complain about targets – doctors do, and the Conservatives are so keen to appease the medical profession that they say they will abolish them. Cameron made a mistake too, I thought, in siding with the easy excuse of NHS managers in whose care patients died of C. diff. superbug infections. They protested that they were distracted by government targets. Yet all the evidence from the Blair years is that, far from diverting from other objectives, meeting targets helps to improve efficiency elsewhere.

True, there are still far too many targets, even after the "streamlined" public service agreements were published earlier this month. And some of them are easy to mock. The plan to increase the proportion of children who have school lunches from 42 per cent, for example. Or the target for people to have more "meaningful interactions", or for young people to take part in more "positive activities". These have not been defined yet, but possibilities include youth groups such as "youth café, scouts, guides, cadets"; the Tufty Club is not mentioned.

But the target regime is also becoming smarter. The target for reducing truancy has been dropped. This is entirely sensible: forcing children who don't see the point of going to school is counterproductive, dealing with the symptom, not the cause. Yet the Conservatives, who normally want to abolish targets, still managed to complain. This kind of inconsistency exposes the difficulty that Cameron has in coming up with a convincing story as to how the Conservatives would make public services better.

He can attack Brown's statist instincts, as he did last week, over the plan – hastily dropped – to claw back financial surpluses from schools. But that is not enough of a programme.

For Blair, Life After Losing and Leaving (in his case it was an unusual mixture of losing to his own party and leaving on his own terms) is busy enough and purposeful enough to keep him occupied. Even in the Middle East, though, he sometimes casts a backward glance. He told Ehud Olmert, the Israeli prime minister, that he should be thankful that lots of people are after his job, "rather than just one".

But Blair is not temperamentally inclined to rubbish his successor, which is just as well, because, after all these years, they still need each other. Blair needs Brown to succeed to validate his record. Brown needs Blair's public service reforms to work to win the election, when he finally decides to "give the House of Commons the power" to decide when it should be.