The idea was first suggested by the Independent Schools Council and the Boarding Schools Association two years ago.
The Department for Education and Skills said it was taking the matter "very seriously".
Oliver Letwin, the shadow home secretary, has said the Conservatives are looking at the issue and the Liberal Democrats say they have supported the idea for some time.
Adrian Underwood, national director of the Boarding Schools Association, said: "We have been talking to the DfES about this for about two years.
"The scheme would identify pupils at primary school-age, where the head and other staff feel they would benefit from a modern boarding school education. We would need to identify who would respond and want to do it.
"It would offer these young people who may - through no fault of their own - have disrupted family backgrounds, a continuity of care. It would give them long-term, 24-hours-a-day pastoral care. It is letting children know where they are going to be.
"It is not appropriate for everybody and no one is suggesting there is a great magic wand."
Mr Underwood said average fees for boarding schools were about pound;16,000 a year, less than the annual costs of a child in care.
Social services estimate that in 200102 the average weekly cost of a child in a children's home was pound;110,708 a year and for foster care pound;16,224 a year.
A DfES spokeswoman said the cost of a child at boarding school being supported during the holidays would also need to be considered.
Boarding schools, Letters 29