However, Mr Johnson seems to stick by the claim as he writes about the benefits the United Kingdom will enjoy once it breaks away from the bloc. The article made no reference to a transition period the government is expected to negotiate.
Remainers said the figure - printed on the side of a Leave campaign bus alongside the words, "Let's fund our NHS instead" - failed to take into account the full economic impact of being part of the European Union, and of the rebate.
In the article for the Telegraph, however, he said the United Kingdom would "roughly" be £350 million better off and it would be a "fine thing" if a lot of it went on the health service.
"Once we have settled our accounts, we will take back control of roughly 350 million pounds (475 million USA dollars) per week".
She is expected to give an update on Brexit negotiations and "will underline the government's wish for a deep and special partnership with the European Union once the United Kingdom leaves the EU", the prime minister's spokesman said.
Mrs Rudd also said Scottish Tory leader Ruth Davidson "has a point" when she criticised Mr Johnson for submitting the piece as London suffered another terror attack.
Will Tanner, a former adviser to May, said the timing was astonishing, self-serving and disloyal.
The "lie" most high-profile of campaign, target weekly of 350 million pounds of contributions to European Union to public health, figure, precisely as head of cartel in its list of promises.