Thousands of Lincolnshire children living below the breadline are missing out on free school meals.
It means the schools stand to lose millions in funding which could otherwise be spent on one-to-one tuition and extracurricular activities.
Anyone who receives state benefits – such as income support or child tax credit – is eligible to apply for a free school meal for their son or daughter.
And the school receives a pupil premium for each child signed up to the scheme – which is set to increase from £623 to £900 from April.
With more than 4,000 children who are eligible not currently claiming free school meals, it means schools could lose £3.6 million in the next 12 months.
Lincolnshire County Council is now rolling out a raft of measures to encourage the take-up of free school meals.
Letters are being sent out to both schools and parents to raise awareness of free school meals. And work is being done to identify why some families are not taking advantage.
The county council's Patricia Bradwell, executive member for children's services, said: "In Lincolnshire, an estimated 4,000 children are currently missing out on free school meals. That leaves parents in poorer households with less money to spend on other essentials.
"So we want more parents to come forward and claim for what they are entitled to – free, nutritious school meals for their children which will help towards a healthy balanced diet."
New research from the Department for Education shows that one in four children, 27 per cent, are currently missing out. This is nearly double the national average of 14 per cent.
Neil Spencelayh, head teacher at Witham St Hughs Academy, near Lincoln, urged everyone who was eligible to sign up for a free school meal. He said: "When pupils are eligible for free school meals, it means the schools can make sure they're getting food in the middle of the day. In many schools, that's a hot meal, which is good brain food.
"Those children also attract additional funding for schools, which can be spent on helping pupils with their schooling and give them the chance to take part in activities they otherwise may not have been able to, which has to be positive."
Jule Holmes, a 48-year-old parent from Lincoln, told the Echo she thought some families may be embarrassed about signing their child up to the scheme.
She said: "I think sometimes there can be a bit of stigma behind parent signing up their child for a free school meal, but it's nothing to be embarrassed about.
"Times are tough and this is something that's there and waiting to help out. It can save you about £15 a week.