In a letter to Boris Johnson published by the Times Educational Supplement, Sir Kevan said he did not believe it was possible to deliver a successful recovery without significantly greater support than the Government has, to date, indicated it intends to provide.

His resignation as education recovery commissioner comes after an extra £1.4 billion announced by Government for its catch-up programme for schoolchildren in England was branded “pitiful” by school leaders.

The money, announced by the Department for Education (DfE) on Wednesday, will be used to offer pupils up to 100 million hours of tuition as part of the Government’s catch-up programme for children in England who have faced disruption due to Covid-19.

The £1.4 billion – made available on top of £1.7 billion already pledged – came under fire following suggestions that Sir Kevan called for 10 times as much to be invested.

In a statement announcing his resignation, he said: “Advising the Government on the education recovery plan has been the most important task of my professional life. The recovery approach we take will reveal our commitment to a generation of children. After the hardest of years, a comprehensive recovery plan – adequately funded and sustained over multiple years – would rebuild a stronger and fairer system.

“A half-hearted approach risks failing hundreds of thousands of pupils. The support announced by Government so far does not come close to meeting the scale of the challenge and is why I have no option but to resign from my post.

“One conservative estimate puts the long-term economic cost of lost learning in England due to the pandemic at £100bn, with the average pupil having missed 115 days in school. In parts of the country where schools were closed for longer, such as the North, the impact of low skills on productivity is likely to be particularly severe. The pandemic has affected all pupils but hit disadvantaged children hardest. A decade’s progress to narrow the attainment gap between disadvantaged children and their peers is estimated to have been reversed.

“As part of the plan I proposed to Government, I recommended a landmark investment in our teachers, whose dedication throughout the pandemic has been inspiring. It is also right to extend access to tutoring, in particular to support disadvantaged children. Tutoring can provide valuable support that complements classroom teaching. But it is not a panacea and must be high-quality to make a difference.

“This is one reason why I recommended schools and colleges be funded to extend school time for a fixed, three-year period and providing significant funding for a flexible extension to school time, equivalent to 30 minutes extra every day. From the perspective of teachers, extra time would have been optional and paid, with schools also able to use the time to offer enrichment activities that children have missed out on.

“The package of support announced yesterday falls far short of what is needed. It is too narrow, too small and will be delivered too slowly. The average primary school will directly receive just £6,000 per year, equivalent to £22 per child. Not enough is being done to help vulnerable pupils, children in the early years or 16- to 19-year-olds. Above all, I am concerned that the package announced yesterday betrays an undervaluation of the importance of education, for individuals and as a driver of a more prosperous and healthy society.”

A No 10 spokesperson said: “The Prime Minister is hugely grateful to Sir Kevan for his work in helping pupils catch up and recover from the effects of the pandemic.

“The government will continue to focus on education recovery and making sure no child is left behind with their learning, with over £3 billion committed for catch up so far.”