The UK’s statistics watchdog has stood by its criticism of Boris Johnson in a row over the possible financial windfall the NHS may get from Brexit.
Sir David Norgrove said he was “disappointed” the foreign secretary had, in an article, revived Leave campaigners’ disputed referendum pledge of £350m a week extra for health.
Aides to Mr Johnson suggested Sir David was concerned only about the headline.
The watchdog said this was not the case and it was a “clear misuse” of figures.
In his 4,000 word piece for Daily Telegraph on Saturday, Mr Johnson said “a lot” of the £350m which Brexit supporters have controversially claimed would be recouped by stopping budget contributions to the EU should be spent on health.
The article, in which he also said he opposed paying the EU to secure temporary access to the single market during a transitional phase, divided Tory MPs with some claiming it undermined Theresa May’s leadership ahead of a crucial speech later this week and amounted to a leadership challenge.
Home Secretary Amber Rudd accused her cabinet colleague of being a Brexit “back-seat driver”, telling the BBC that while it was fine for Mr Johnson to show his enthusiasm for Brexit, he should remember he was not “driving the car”.
The chair of the UK Statistics Authority wrote on Sunday to Mr Johnson setting out his concerns about the £350m figure, the frequent use of which – including on the Vote Leave campaign bus – it previously criticised during the 2016 referendum claim.
“I am surprised and disappointed that you have chosen to repeat the figure of £350 million per week, in connection with the amount that might be available for extra public spending when we leave the European Union,” he wrote in the letter.
The watchdog said the article “confused” the size of the UK’s annual gross and net contributions to the EU’s budget.
His letter continued: “It also assumes that payments currently made to the UK by the EU, including for example for the support of agriculture and scientific research, will not be paid by the UK government when we leave. It is a clear misuse of official statistics.”
The foreign secretary’s spokesman said later the two men had spoken and insisted Sir David was complaining about the headline on the newspaper article rather than his words.
But a spokesman for the UK Statistics Authority said: “Sir David Norgrove does not believe the issues lie solely with the headlines. He has not changed the conclusion set out in his letter to the foreign secretary.”
Labour MP Yvette Cooper said Mr Johnson was aware of the different budgetary calculations and knew the “problem is his £350m, not just headline,” adding he “just thinks it’s OK to repeatedly lie”.
Lib Dem leader Vince Cable said : “I’m glad to see the independent UK Statistics Authority has the courage to slap Boris down. It’s a shame the same can’t be said of Theresa May.”
Earlier Mr Cable said Mrs May’s authority would be undermined if she did not remove Mr Johnson following on from his article in Saturday’s Telegraph but the BBC understands the foreign secretary will not be sacked, despite anger among some MPs.
Several Tory MPs have praised Mr Johnson’s vision of what can be achieved after the UK leaves and said his objectives are largely in tune with those of the government.
Ms Rudd said she did not believe it was a prelude to a leadership challenge, rather a case of “back-seat driving” from the foreign secretary.
“I know what an irrepressible enthusiast (Johnson) is about Brexit, and what he’s done is set it out there, I think it’s absolutely fine, I would expect nothing less from Boris,” she said.
But she added: “I don’t want him managing the Brexit process, what we have got is Theresa May managing the process, driving the car.
“I am going to make sure, as far as I and the rest of the cabinet is concerned, we help her do that.”
Several prominent Leave campaigners have distanced themselves from the £350m figure in the wake of the referendum result although others have continued to insist it is legitimate.
After his article’s publication Mr Johnson later tweeted he was “all behind Theresa for a glorious Brexit”.
The prime minister is due to make a major speech on Brexit in Florence, amid speculation she is prepared to announce some kind of deal on transitional trade payments.