The mayor of London Boris Johnson wants to enter the capital into influential global education rankings to see how it compares to international competitors, TES can reveal.

A separate Programme for International Student Assessment (Pisa) entry for the city would be a first in England. Until now the nation’s performance has been measured as a whole.

Writing in an annual report on London education being published tomorrow, Mr Johnson states that: “London is leading the UK at every stage of young people’s education”.

Now his office wants to see how the capital’s improved education would match up against the world’s highest-ranking school systems.

Deputy mayor for education and culture Munira Mirza said: “We are investigating whether it would be possible to get a Pisa grading specifically for London, which would make it much simpler to present how well London is performing against our international competitors”.

Between 2003 and 2011 London moved from being the lowest-performing of England’s nine regions for GCSE results to the highest-performing, and it has stayed there.

Ms Mirza suggested this would translate into a correspondingly high Pisa performance. “We see ourselves as competing with the success to be found in other high-performing countries around the world, and it is likely that if the rest of the country performed as well as London educationally, the national Pisa ranking for maths and English would rise from a current position of 27th to around 17th,” she said.

Mr Johnson will be pushing at an open door as far as the Organisation for Economic Cooperation and Development (OECD), which runs Pisa, is concerned.

Earlier this year the organisation’s education director, Andreas Schleicher, told MPs that he had been calling for a separate London entry.

“We have encouraged the UK actually to collect separate data for London like many other countries have [for their cities] already,” he told the Commons’ Education Select Committee in March.

“We believe that’s an interesting dimension to look at, to compare the performance of large cities.”

But Mr Schleicher warned that the UK capital would still probably not match the achievements of the systems that Pisa ranks as the best in the world, such as Shanghai, Hong Kong and Singapore.

“I would still, this is a guess that I make now, but I would still think that you would find a very large performance difference between Shanghai and the city of London,” he said. “Probably London will outperform the rest of the country, I think there’s good national data for this. But when I look at your national data, you’re not going to be anywhere close to some of the city states.”

Russell Hobby, general secretary of the NAHT headteachers’ union, said that on one level a separate ranking for London would be “fairer” because China had been able to do the same for Shanghai.

But he added: “We need to be concerned with the education of every single child in this country, and part of the problem is London seems to pulling away in performance and we need to turn our attention to other communities that have been neglected over years.

“I can completely understand why London would want to celebrate its success. But as a national issue it is not a high priority.” 

One researcher, who has studied London’s success, has cast doubt on the validity of the comparison between GCSE results and Pisa rankings.

The mayor’s office said: “This assumption is based on early exploratory work carried out by the Department for Education to equate GCSE grades to Pisa scores and formulate a ranking for London (and other regions too) based on 2012 Pisa results.”

But Loic Menzies, who co-authored a major report on the success of London schools published earlier this year, said the findings “should be treated with huge caution”.

He pointed out that GCSEs and Pisa tests were “completely different assessments” and therefore not directly comparable. Further caution was needed because Pisa rankings were based on “finely balanced” comparisons between scores with large margins for error, he said.

London’s relative success will be discussed at an education conference organised by the mayor’s office tomorrow.  

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Compare London’s schools with Shanghai and Singapore, urges Pisa boss March 7 2014