Babies born in England during the Covid crisis have been slower at developing key language, cognitive and social skills, and the veteran education policymaker Sir David Bell is warning that rapid intervention is needed to stop those children being left further behind.

More than 80,000 children born in 2020 or 2021 did not reach one or more of the key measures of progress for their age group last year, according to official data highlighted by Labour’s education team, including 60,000 very young children who did not develop communication abilities usually seen in children their age.

Writing in the Guardian, Bell – who is chairing Labour’s review of early childhood education – said nursery closures and “eye-watering” childcare costs meant many two-year-olds were unable to receive high-quality early years education to make up for the “crucial experiences” they missed during the Covid crisis.

“It’s no wonder that headteachers have spoken of children arriving at school who are still wearing nappies, whose communication abilities are limited, or who are still unable to use a knife and fork,” said Bell, a former primary school teacher who later served as the permanent secretary at the Department for Education and the chief inspector of Ofsted.

“Despite the best efforts of teachers, gaps in learning and development widen as children grow older, becoming embedded and therefore more difficult to overcome.

“Prevention is better than cure, which is why we need to intervene early to prevent educational gaps from developing before they can grow. This will require a clear plan from the government. Yet its support has so far been lacking.”

Bell said creating a “new, modern childcare system” to eradicate those gaps would not be easy.

“Britain has a broken economy, an exhausted workforce and rising child poverty. Local government and public services have been hollowed out. But we cannot afford to fail,” he said.

The official data showed that national rates of child development last year were lower among two-year-olds than in 2018-19, before the pandemic, with London reporting the worst rate of development among children surveyed.

There were also sharp disparities between England’s local authorities. Nearly 95% of children aged between two and two and a half in Wokingham, Berkshire achieved or bettered all five development targets including problem solving and social skills, compared with 44% of the same age group in Brent, north London.

With the general election approaching, Labour is pushing early years education and post-Covid recovery as one of its key policy offers with a wide appeal to parents and grandparents as well as employers.

Bridget Phillipson, the shadow education secretary, said: “That so many of our youngest children are missing the crucial building blocks that lay the foundation for their future life chances is nothing short of a modern-day scandal.

“Labour’s plan for reform of early years will be informed by a review led by the respected former Ofsted chief inspector Sir David Bell but we will also work with early years settings to develop ‘maths champions’ and offer innovative early speech and language interventions to help children still affected by the impacts of the pandemic.”

The government has also been active with increased funding for the early years sector in England. In last year’s autumn statement, it announced an additional £400m funding for the sector to cover staff pay increases and up to £1,200 for new childminders joining the profession, in an effort to tackle longstanding staff shortages.

And earlier this week applications opened for the government’s expansion of funded childcare provision in England, with working parents able to claim 15 hours a week during term time from April. By September 2025 the government aims to offer 30 hours of childcare a week, for 38 weeks a year, to all eligible children from nine months old.

Gillian Keegan, the education secretary, said the latest expansion would make sure that “parents no longer have to choose between a career and a family”, getting more people into work and growing the economy.

But Bell said while the expansion to children as young as nine months old sounded appealing on paper, in reality the government’s promises would be undeliverable.

“Many nursery providers are already saying they will not offer these new entitlements, meaning families will continue to struggle to get the childcare they need. The government rushed out an announcement in an attempt to score political points. It is the equivalent of saying, ‘We’ll treat 100 more patients – we just have to build the hospital first.’”

“There is no plan to recruit the staff needed to care for more children. There are no proposals for how these new nursery places will be delivered, nor how to solve the problem of childcare deserts that exist across the country,” Bell said.