More than one in five pupils in England are eligible for free school meals as numbers of needy children swelled to 1.9 million.
Figures from the Department for Education (DfE) reveal a surge in the proportion of youngsters who qualify for free lunches, rising by around 160,000 in January from 1.74 million last year.
Heads said it was "shocking" that 22.5% of pupils qualify for the benefit, compared to 20.8% in 2021, as families struggle with increased cost of living pressures.
Pupils in the North East were the most likely to qualify for free school meals on 29.1%, followed by the West Midlands, where 26.5% are eligible for free lunch provision, according to the annual school census.
By contrast, 17.6% of pupils are eligible for free school meals in the South East and 18.2% of pupils are eligible in the East of England.
Rates have surged across the whole country, with the highest increases in London and West Midlands with increases of 2 percentage points since 2021.
However, all regions show some increase from 2021.
Children from Irish Traveller families were most likely to qualify (63%), followed by Gypsy/Roman pupils (51.9%), and youngsters of mixed Black Caribbean/White heritage (41.5%).
Rates were lowest among pupils of Indian (7.5%) and Chinese ethnic groups (7.8%).
Pupils are able to get free school meals in England if their parent or carer is entitled to benefits such as income support or receives Universal Credit on an income of less than £7,400 a year.
Unions and school leaders have put pressure on the Government to expand provision to all families receiving Universal Credit as the cost of living crisis reignited the row over widening eligibility.
Scotland and Wales have already committed to broadening provision.
Julie McCulloch, Director of Policy at the Association of School and College Leaders, said: "It is shocking that in one of the world’s wealthiest economies we are seeing a very significant increase in the number of children eligible for free school meals, and therefore living in extremely difficult financial circumstances."
She said the rise may be linked to changes in benefit payments as well as the ongoing hit to family finances from the pandemic.
Ms McCulloch added: "Their circumstances will become even more severe because of the cost-of-living crisis."
Paul Whiteman, general secretary of school leaders' union NAHT, said members had described the "shocking and stark" rise in poverty in their school communities over the past years.
"It is clear that the combined pressures of Covid-19 and the cost-of-living crisis have driven more families and children into poverty," he said.
“The children who have newly become eligible for free school meals are disproportionately drawn from more disadvantaged areas and are largely those pupils who already needed more support, which schools are increasingly struggling to give with over stretched budgets and the erosion of the value of pupil premium funding since 2015.
The DfE said the percentage of pupils eligible for free school meals had been "increasing prior to COVID-19 pandemic", up from 13.6% in January 2018, to 15.4% in January 2019, and to 17.3% in January 2020.
Numbers soared after the first lockdown, whereas the latest rise is "in line with those increases seen prior to the pandemic", the department said.
A Government spokesperson said: “Over 1.9 million children are now eligible for free school meals, and we communicate regularly with schools and councils so they know what is available for these children.
"We know millions of families are struggling with the rising cost of living, which is why we are providing over £37 billion to target those with the greatest need.
"Our National School Breakfast Programme and the Holiday Activities and Food programme are also benefitting children across the country."
