Families are not aware they could claim for free school meals
A fifth of low-income families in England are not even checking to see if they could claim free school meals for their children, suggests a survey.
The School Food Trust, which promotes healthier school meals, says this means that families are missing out on benefits worth about £700 per year.
"Many parents simply do not know that they can claim," says the trust's chief executive, Judy Hargadon.
Figures earlier this month showed an increase in pupils who would qualify.
The survey from the School Food Trust suggests that one in five families likely to qualify for free school meals were unaware whether they would be eligible.
The trust wants to raise awareness among parents of the entitlement.
"As the recession bites and unemployment rises, cash-strapped families need to be making all the savings they can. We would urge any parent to check with their school or local council and start claiming what's theirs," says Ms Hargadon.
A spokeswoman for the trust said there appeared to be some confusion about entitlement - such as parents who work part-time thinking that they would not qualify.
There are also suggestions that parents might not want their children to feel stigmatised by being identified as coming from a low-income family.
Jackie Schneider, chair of a parents group in the London borough of Merton, suggests that schools should make arrangements so that payments or the allocation of free meals should be in private.
"We want all schools to make it impossible to tell who 'pays' for lunch or not, so that no child could ever feel embarrassed about claiming what's rightfully theirs," she says.
This year's annual census of schools in England showed an increase of more than 21,000 in the number of pupils eligible for free school meals - an increase attributed to rising unemployment.
The 2009 census showed a rise in free school meal pupils from 15.5% to 15.9% in primary schools and from 13.1% to 13.4% in secondary.
This national average included wide regional variations - from 47.5% of primary pupils in Tower Hamlets to 4.2% in Wokingham.