The government has pledged 100,000 more nursery places in England, but early development specialists fear that primary schools may not have the room, specialised equipment, or staff to carry on this promise.

Labour faces tremendous pressure to open up enough spaces in order to achieve its commitment, carried over from the previous government, to provide eligible parents of children aged nine months to three years with 30 hours of free childcare per week starting in September of next year.

In the first phase of Labour's proposal, 300 new state nurseries will open in England by September of next year at primary schools that have empty classrooms due to declining birthrates, according to a statement made last week by Education Secretary Bridget Phillipson.

However, experts caution that the £15 million in capital money allocated for this phase could not be sufficient to pay for the expenses associated with getting schools ready to welcome these very young students.With poorly paid staff hard to find and retain, and existing nurseries finding it hard to balance their books, they also questioned whether enough cash-strapped schools would want to step into early childcare.

Dr Aaron Bradbury, lecturer in early childhood at Nottingham Trent University, said: “You can’t just say: ‘I’ve got a free classroom – let’s turn it into a nursery.’ The space and the facilities you need are completely different.”

He said the idea of using primary schools was a reasonable one, but “it needs a much more thought-out plan”.

He added: “A classroom has got 30 children sitting at tables, but two-year-olds are very different. They need space to develop and learn through play.”

Bradbury said that as well as facilities such as small-size toilets and a door into an outdoor play area not used by the older children, schools may end up spending thousands on adaptations such as moving windows lower down so that very small children can see out of them.

For children under two, schools would need a separate space for them to sleep in, kitchen facilities to sterilise bottles, toilets and a calm, quiet area to change nappies, he said.

Sue Cowley, an expert on behaviour in schools, who has co-run her local preschool for more than a decade, said: “I’m not sure schools will want to take nine-month-olds. The ratios of staff to children are really high, so it is tough to make the funding work, and it can be harder to find staff who only want to look after babies.”

Even with children of two years and older, some experts are saying empty classrooms will not be big enough. Cowley said: “For this age, you need lots of space for all the different areas of learning. For instance, inside, we have a sand tray, a climbing frame, a book corner where they sit to read, an art area and so on.”

Paul Whiteman, general secretary of the National Association of Head Teachers union, confirmed that some schools had already been considering setting up nursery provision and would be pleased to get started, but stressed there needed to be “meaningful action to tackle the current workforce crisis the early years sector is facing” if these nurseries were to succeed.

A survey this summer by the Early Years Alliance, which represents 14,000 providers of care and education to under-fives in England, showed that nearly 80% of providers had found it difficult to recruit staff in the past year. More than six in 10 also reported that staff had left the sector entirely in the last six months.

"I don't recall a secretary of state ever saying: 'My No 1 priority is early years,' as Bridget Phillipson has," stated alliance CEO Neil Leitch.

However, he continued, saying, "The opposition narrative doesn't always become the reality of office, even though the rhetoric is correct and the intention is sound." Leitch stated that while poor pay was a major factor in people quitting or not choosing the field, particularly in times of high cost of living, many people were also departing because they felt "undervalued and exhausted."