The head of Ofsted has warned that more needs to be done to support children who are “being left behind”, as she criticised poor social mobility at the launch of her second annual report.

Amanda Spielman used this year’s report to issue a call for action to the government “redouble their efforts to tackle these challenges and drive up standards in the years ahead”.

Speaking at the official launch in Westminster, Spielman said there are children “for whom it seems the die is cast, even before entering nursery, and who never catch up in 12 years of schooling”.

Wealth “remains a predictor, albeit a weaker one, of educational performance”, she said.

Spielman said the best way to reduce inequality in education amongst children from different backgrounds was to “get the basics right”, and criticised policymakers for “constantly looking for the next magic potion that will infallibly raise standards or reduce the numbers of children in care”.

Ofsted is preparing to strengthen its focus on early reading in the new inspection framework, as Spielman warned that the percentage of children on free school meals who reach the expected standard on the phonics screening check is 12 percent lower than their most affluent peers.

The report warns that off-rolling, a process by which pupils are removed from schools without formal exclusions, has become a “huge cause for concern” for the watchdog. Research released earlier this year revealed that 19,000 pupils dropped off school rolls between years 10 and 11 between 2016 and 2017, and around half did not reappear at another state-funded school.

Ofsted’s new framework will encourage inspectors to report on schools who participate in off-rolling, the watchdog said.

The annual report also warned that the “capacity for improvement does not exist” in provision for young people with learning difficulties, and found that the “gap in performance and outcomes for children with SEND is widening between the best and worst local areas”.

Spielman warned that “attainment, progress and aspiration” in coastal towns and white working class communities are “too low”. Although the report finds that 86 per cent of schools are rated as ‘good’ or ‘outstanding’, a statistic heralded by the government as a sign its reforms are working, Spielman warned that some 500 schools have not improved for more than a decade.

The chief inspector also used the report to criticise the academy system. The report argues that “the current half-way house approach to academisation is not working” and calls for better incentives to encourage the best schools to become academies and use their expertise to sponsor.

“Across the whole education sector, a mentality of ‘what’s measured is what gets done’ trumps the true purpose of education and curriculum thinking – the consideration of what needs to be taught and learned for a full education – has been eroded.

“Schools have become another front in the new culture wars, expected to tackle an ever growing list of societal issues,” Spielman said.

A spokesperson for the Department for Education said: “This report shows that standards in our schools are rising, with 86 per cent judged to be good or outstanding compared to only 66 per cent in 2010. It shows we have a robust education system – one where parents can feel assured that the vast majority of schools, early years providers, children’s homes and local authorities provide a high level of education and care for young people, regardless of their circumstances.

“One of the key functions of a good regulator is that it highlights areas of concern and we will work with Ofsted, schools, local authorities and others to address the issues this report picks out.”

Ofsted’s new inspection framework will be consulted on in January, and is expected to take effect in September 2019.