In a press release from the mayor’s office on 21 February, Johnson used figures taken from Transport for London’s latest quarterly statistical bulletin – which had not yet been published – to claim that robbery and criminal damage on public transport had fallen dramatically in recent years.

Transport for London is not currently required by law to adhere to the authority’s code of conduct on statistics, but in a letter to Johnson, Michael Scholar, who chairs the UK Statistics Authority, said the early release of certain numbers from the body’s quarterly statistical bulletin was “damaging to public trust” and called on the mayor to comply with the code “as a matter of principle”.

Scholar added that he would be writing to the Home Secretary Theresa May and the Minister for the Cabinet Office Francis Maude “to express the view that Transport for London’s statistics should be reclassified as official statistics”.

A spokesman for the mayor pointed out that Scholar had not questioned the accuracy of the statistics, adding: “We are happy to look at the suggestions he has made.”