The Yorkshire Post Says: May must seek full backing of Cabinet over EU speechThe Environment Secretary, who spectacularly torpedoed Mr Johnson's run for the Tory leadership after the Brexit vote, expressed support for his Cabinet colleague and accused critics of trying to "refight" the referendum.
The claim first attracted criticism during the referendum campaign, when Mr Johnson and Mr Gove were travelling around the country in a bus emblazoned with the slogan "We send the EU £350 million a week let's fund our NHS instead".
The Foreign Secretary's decision to revive it in a 4,000 word article at the weekend prompted statistics watchdog boss Sir David Norgrove to publish a letter to Mr Johnson saying he was "surprised and disappointed", claiming it was a "clear misuse" of official figures.
Mr Johnson responded with his own letter accusing the UK Statistics Authority chairman of a "complete misrepresentation" of his views and called on him to withdraw the criticism.
He claimed the statistics boss had privately conceded he was "more concerned by the headline" and the coverage of the controversial article and "accepted that I was not responsible for those".
But a spokesman for the chairman stood by his accusation and said the Foreign Secretary's riposte "doesn't alter his view".
On Monday, Mr Gove backed Mr Johnson, tweeting: "In the debate on EU contributions it's important people look at what Boris actually wrote in his Telegraph article, not headlines.
"Debate should be forward looking on how to make most of life outside EU, not refighting referendum".
It is not the first time the £350 million figure has been disputed by the Authority.
The watchdog initially warned Vote Leave the number lacked "clarity" because it referred only to the UK's gross annual contribution and did not take into account Britain's rebate or money that comes back from the EU.
In his Daily Telegraph article on Saturday, Mr Johnson wrote: "Once we have settled our accounts, we will take back control of roughly £350 million a week.
"It would be a fine thing, as many of us have pointed out, if a lot of that money went on the NHS, provided we use that cash injection to modernise and make the most of new technology."