The BBC today accused Boris Johnson of lying after he demanded Theresa May honour the Vote Leave vow to save £350million from the EU and spend it on the NHS.
The Foreign Secretary revived the controversial claim in an explosive Brexit manifesto seen by many as a leadership.
But in a 'reality check' feature, the BBC said the figure did not add up.
Senior Brexiteer Andrew Bridgen told MailOnline the BBC should not be acting as if it was 'running the Government'.
The BBC today accused Boris Johnson of lying after he demanded Theresa May honour the Vote Leave vow to spend £350million a week on the NHS
In a 'reality check' feature (pictured), the BBC said the claim was 'wrong' and did not add up
The article said because of Britain's EU rebate, only £276million was sent to the European Union each week.
And much of that money is returned in things like farming subsidies and grants - all of which would have to be cancelled to spend Britain's entire EU budget on the NHS.
Mr Bridgen told MailOnline: 'I did not know the BBC were running the government and deciding spending commitments.
'If a majority of MPs in Parliament decide we are going to spend most of the money we get back from the EU on the NHS, that is what will happen.'
Mr Johnson's 4,000-word feature - which appeared on the front page of yesterday's Daily Telegraph - claimed that after Britain had 'settled its accounts' with the EU, Britain would be around £350million a week better off.
He said: '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.'
Since the referendum campaign, many on the Leave side - including even ex Ukip leader Nigel Farage - have accepted the policy is not deliverable.
Mr Johnson has been widely condemned by Remain supporters for resurrecting the pledge, which was famously painted on the side of the Vote Leave bus.
Liberal Democrat leader Sir Vince Cable said: 'On his central point, the £350m a week, this is a lie.
'He knows it is a lie and endlessly repeating it does not make it the truth.'
Labour leader Jeremy Corbyn said Mr Johnson's comments 'laid bare the conflicts at the heart of Theresa May's government over Brexit' and undermined the prime minister's authority.
He said: 'The foreign secretary even has the gall to dredge up the fantasy of £350m a week extra for the NHS.
'The prime minister must spell out now how this will be paid for, or stand condemned for once again trying to mislead the British public.'
The £350million a week figure was debunked during the referendum campaign by Sir Andrew Dilnot, the head of the UK statistics watchdog.
Boris Johnson is 'back seat driving' the Brexit negotiation and he should stop interfering, Home Secretary Amber Rudd
Boris Johnson was accused of 'back seat driving' the Brexit talks today as a Cabinet row exploded into public view.
Home Secretary Amber Rudd blasted 'I don't want him managing the Brexit process' and urged the Foreign Secretary to leave the talks to Theresa May.
Mr Johnson stunned Westminster with a 4,000-world article setting out his personal vision for Brexit yesterday in what many saw as a brazen leadership bid.
No 10 has scrambled to insist the Government is united less than a week before Mrs May makes a major Brexit intervention with a speech in Florence.
Ms Rudd used a major TV interview today to give a glimpse into the fury at Mr Johnson's intervention.
Home Secretary Amber Rudd (pictured on the Andrew Marr show today) accused Boris Johnson of 'back seat driving' the Brexit talks today
She famously told a TV debate during the referendum campaign she would not want Mr Johnson 'driving her home at the end of the evening'.
Ms Rudd said she had not read Mr Johnson's piece as she had 'quite a lot to do' responding to the Parsons Green terror attack.
And today she told the BBC's Andrew Marr that Ruth Davidson 'had a point' in suggesting the timing of Mr Johnson's intervention was unhelpful.
She said: 'I had a very busy weekend dealing with what could have been a terrible attack on our transport system.'
Ms Rudd added: 'I have the great good fortune to work with Boris. I know what an irrepressible enthusiast he is about Brexit and what he has done is set it out there - I think it's fine and I would expect nothing less.
'I don't want him managing the Brexit process. What we have got is Theresa May managing that process, driving the car to continue the allegory.
'I am going to make sure that as far as I cam concerned and the rest of the Cabinet is concerned, we help her do that. This is difficult moment.'
Prompted to agree Mr Johnson was back street driving, she said: 'You could call it back seat driving.'
Ms Rudd said 'time will tell' if Mr Johnson's article was a 'helpful intervention'.
Ms Rudd used a major TV interview today (pictured) to give a glimpse into the fury at Mr Johnson's intervention