Conservative peer Lord Lansley, architect of the controversial Health and Social Care Act implemented under the coalition government in 2012, told the Health+Care conference in London that he had not expected the NHS to feature in the EU referendum debate.
As health secretary, he said 'Europe didn't tell me what to do'.
But he added that after the NHS featured heavily in the campaign, 'there may be those quite understandably in the NHS who are expectantly waiting for £350m a week to turn up'. But referring to the £350m pledge, he said: 'Frankly, it was never remotely correct.'
The former health secretary added: 'Even on the basis of the most generous assumptions once you've discounted for the returns to the UK from our EU contributions, probably it's about £120m a week is the maximum amount that could be available. And that was promised to a wide variety of supplicants who have now started putting in their chits.'
Lord Lansley told the audience that the case for an increase in NHS funding in the autumn statement was now 'inescapable'. The government would have to find new investment in the health service despite the likely negative impact of Brexit on the economy, he added.
'My expectation six years ago while we were asking the NHS to live with real terms increases that were tiny, was that that would not be sustainable for the long term. There would come a time when the NHS would need to return to trend levels of increases in spending - in the region of 3% real per annum.
'With increases in population, changes in demographics and the impact on the NHS of changes in social care funding that is now inescapable.'
Lord Lansley added that since both sides in the referendum campaign had pledged that their camp coudl deliver more NHS funding - either through a stronger economy or cash clawed back from the EU, they should be held to that promise when the autumn statement was made.
He said an increase in funding for the NHS was vital because 'I don't regard the £22bn efficiency saving [targeted by the NHS] as likely to be achieved in this parliament.'
Mr Lansley warned that research organisations were 'distraught' about the potential impact of Brexit, and that the government would have to ensure that vital staff from EU nations working in the UK health and care sector were not lost.
He added that the government 'did not have a plan' for the post-Brexit UK. 'We need a plan and need a list. Health and care should be at heart of what we set out to do in a treaty with the EU.'