Steve McCabe, the minister's parliamentary private secretary, writing in today's TES (below) says that providing all primary pupil with free meals would significantly cut obesity and behaviour problems.
Mr McCabe, MP for Birmingham Hall Green, believes the move could be relatively straightforward because money could be diverted from 20 government initiatives aimed at encouraging children to eat healthily.
More than pound;173 million is spent on the campaigns each year, which could provide all children with school meals for two terms at current take-up rates. Additional money could come from the lottery's New Opportunities Fund, which spends pound;42m - the cost of 26 million lunches - on providing schools with fruit.
The suggestion is one that education ministers and the Department for Education and Skills appear to be taking seriously.
Stephen Twigg, the minister for school standards, told the House of Commons this week that it was "vital" the plan was considered.
Kingston-upon-Hull will next month begin piloting a scheme where all primary pupils will get free lunches and breakfasts.
Mr Twigg said he would be visiting Hull next week and would monitor its progress closely. "It will be interesting to consider the impact that the take-up of the meals has on the children's education, their health and their behaviour," he said.
The idea that primary pupils should receive free meals was also proposed separately this week by Tom Watson, the Labour MP for West Bromwich East, in the spring issue of Fabian Review.
A poll of viewers by the Channel 4 programme Richard amp; Judy this week found that 70 per cent were in favour of the idea.
Mr McCabe said it made sense to provide lunches even for children whose families could afford them because of the long-term health benefits for the country.
Research suggested a link between attention deficit disorder, a prime cause of misbehaviour in the classroom, and vitamin B deficiency, he said.
"I'm asking the Government to stop tinkering at the edges and put its money where children's mouths are," he said. "Worldwide research shows that good nutrition improves children's behaviour yet many school meals currently comprise reheated burgers and pizza full of mechanically-retrieved meat products and monosodium glutamate."
Chris Davis, chairman of the National Primary Headteachers Association, applauded the MP's idea and said it would encourage pupils to eat more healthily.
At Mr Davis's school, Queniborough primary in Leicestershire, take-up of school lunches has dropped to a quarter, but numbers double on Fridays when chips are served.