perhaps it was designed to be in keeping with his claim to be “passionate about education”, but at times Gordon Brown’s education policy speech at Mansion House last week sounded like he was preparing for another marriage.

There was something old, with pledges to tackle bullying and bring the private and state sectors closer together. And there was something new, with the National Council for Educational Excellence and extra provision for pupils from low income families.

There was also something borrowed, as he disappointed those on Labour’s left by adopting Tony Blair’s goal of greater diversity, with every school achieving either trust, academy or specialist status.

And there was rather a lot of blue, as Mr Brown hijacked most of the ideas that the Conservative education team have sought to make their own in recent months.

A speech that at first glance seemed to have the aim of improving education was in fact deeply political and could leave the Tories struggling for distinctive policies.

Mr Brown trampled all over their tried and trusted themes of independence for heads and better discipline before stealing their idea of making it easier for organisations to sponsor academies.

Most mischievous of all was his call for setting to become the norm for all schools in key subjects. The Conservatives have been saying something similar for months, but recently David Cameron suddenly switched to talk of a “grammar stream” in an attempt to placate traditionalists angry at his party’s rejection of the 11-plus.

The idea of more rigid streams as opposed to sets has alarmed school leaders, a fact that Mr Brown aimed to exploit to the full.

Much of what he proposed will simply involve spreading practices already applied in some schools across the rest of the system. That is the case with setting, business partners and the links that schools will be expected to make with arts, cultural and sporting communities and other schools in their areas.

The same is true of the improved links between state and private schools, on which Stephen Munday, the headteacher of Comberton village college in Cambridgeshire, and Edward Gould, the former head of Marlborough College and former chair of the Independent Schools Council, have been asked to advise.

Mr Munday, who has made collaboration with outside organisations a virtue at his school, said: “I am absolutely sure there is scope for more of this to go on. We do better together than we do apart. No one holds the fount of all knowledge and being prepared to work together is essential.”

Echoing the call by James Callaghan, the Labour Prime Minister in the 1970s, for a “great debate” in education, Mr Brown called for a national debate on how Britain could move to becoming “world class in education”.

But the Sutton Trust education charity said its research showed that in terms of social mobility, Britain had the worst record in the world. Sir Peter Lampl, the trust’s chairman, said it was a socially selective system.

“The top 20 per cent of our secondary schools - independents, grammars and leading comprehensives - are effectively closed to those from non-privileged backgrounds,” he said.

Lord Adonis, who was tipped to keep his job as schools minister in this week’s reshuffle, rebutted this argument. “Social mobility will only improve tomorrow if we can close the gap in educational attainment today,”

he said.

He proposed a new target for 80 per cent of all pupils to achieve at least five good GCSEs by 2020.

Blair’s ideas man, page 28