Ed Miliband has been criticised by the UK statistics watchdog over his claim that "four out of five" new jobs were being created in London.

Sir Andrew Dilnot said official statistics suggested the reverse was true and only 21.7% private sector jobs had been created in London.

The Labour leader made the jobs claim as he launched proposals to devolve more economic power to English cities.

The Conservatives are calling on Mr Miliband to apologise for the error.

In quotes released to journalists before a speech on regional development, Mr Miliband said: "Independent experts say four fifths of all the new private sector jobs created since 2010 are in London. We know that's not good enough."

'Off the cuff'

The line was not included in the version of the speech Mr Miliband delivered the following day in Leeds - but it was widely reported in the media.

At the time, a spokesman told the Evening Standard: "Ed stands by the words fully, but he decided to speak off the cuff rather than from a script."

The statistic had been taken from a report by the Centre for Cities think tank.

In a letter to Mr Miliband and shadow business secretary Chuka Umunna, Sir Andrew, chairman of the UK Statistics Authority, said "no official statistics are available showing the number of 'new jobs' ".

Image caption Matthew Hancock is calling on Ed Miliband to apologise

He said the Centre for Cities figures were based on the assumption that all people employed in a particular sector, such as health or residential care, were in the public sector - not an approach recommended by the Office for National Statistics (ONS).

There was also a problem with the period quoted by the Labour leader.

"The Statistics Authority encourages all those engaged in political debate to be clear about the sources of their statistical statements, and to be clear on the time period being used," wrote Sir Andrew.

"In this case, the time period for the statistics was referred to as 'since 2010', while the underlying data from Centre for Cities appears to relate only to the period 2010-12."

He added: "Taking these various factors together, there is a wide difference between the statements made about London and the most recent official statistics published by ONS."

'Deeply embarrassing'

The official statistics show that 21.7% of the increase in private sector employment in Great Britain between 2010 and 2014 was in London, said the watchdog.

Matt Hancock, the Conservative MP and business minister who complained to the statistics watchdog, said the error was "deeply embarrassing" for Mr Miliband.

"Ed Miliband should apologise for this error straightaway," he said.

"If he can't get his facts right on the economy, then there is no way he would be able to run the country."

But the Centre for Cities think tank said it was standing by its figures.

Chief executive Alexandra Jones said: "The discrepancy between the figures published in our report and the ONS' data reflects a different definition of the public and private sectors.

"For instance, the 'official' figures count universities as private sector bodies and GPs as private sector jobs, however we regard these as so intrinsically linked to public policy and government funding decisions, that they are better understood as falling within the public sector.

"While any kind of 'broad brush' measure will never be perfect, we continue to regard our definition as the most accurate way in which to make sense of changing trends in employment in UK cities."