The fall in the number of children claiming for free school meals fails to reflect the real deprivation facing many families and is starving schools of resources aimed at needy pupils, heads are warning.
Today's school census statistics, published by the Department for Education, reveal that only 14 per cent of pupils were eligible for and receiving free school meals in January 2017 – the lowest proportion since 2001, when records began.
A document containing the figures states: "Entitlement to free school meals is determined by the receipt of income-related benefits. As the number of benefit claimants decreases, the proportion of pupils eligible for free school meals also falls."
But heads say that, while fewer of their pupils' parents may be claiming benefits, they still appear to be facing similar levels of deprivation.
Jack Sloan, headteacher of Hanover Primary school, in London, said the issue was hitting his school budget because he had less pupil premium funding to help children facing severe disadvantages.
He said: "We're seeing the number of children entitled to the pupil premium dropping. One way of interpreting that may be that unemployment is reducing.
"But other factors that are having a negative impact on family life are increasing – we're seeing children becoming more needy and more deprived in various ways."
He suggested that this could be partly blamed on the quality of available work, pointing to the rise of zero-hours contracts and shift work.
"It may be that more people are in work, but the type of work is different – there are more parents working shift work, or doing two to three jobs, and we're seeing a significant rise in stress among the parents," he said.
Parents have to register for free school meals, and fewer have done so since the introduction of universal infant school meals. But this does not fully explain the fall in FSM eligibility, as the decline is just as steep among secondary pupils.
Could changes to the eligibility criteria for out of work benefits be behind the change? A Child Poverty Action Group spokeswoman said it was more likely that parents of previously eligible pupils had found employment. But, she said, this did not mean they were not struggling.
The spokeswoman said: “As the employment rate rises, eligibility for free school meals will fall, but many working families are really struggling. Two thirds of children living under the poverty line have a working mum or dad.”
Geoff Barton, general secretary of the ASCL headteachers union, said that parents may be less likely to register for the child to have free school meals due to increasing "stigma", as awareness about the pupil premium has grown.
"My impression is that parents are increasingly squeamish about having their child on FSM," he observed.
Some parents might also be put off by "complicated" registration processes, he said. "Eligibility for FSM is no proxy for poverty. A decline doesn't indicate we have less of these needy pupils – we all instinctively feel that there are more."
Russell Hobby, general secretary of the NAHT headteachers union, said the decrease in pupil premium funding was affecting school budgets. He said: "The schools that are in the most challenging circumstances will be slightly harder off as a result."
The trend "suggests that we need to look at how we measure the different challenges students face", he said, adding that working families were often just as needy as those with out-of-work parents, but "often have less help offered to them."