The "big, big problem" of Bangladeshi under-achievement is to be tackled by a new Government campaign.
A joint strategy from the Bangladeshi High Commission and the Department for Education and Employment aims to prevent pupils visiting relatives abroad during term-time.
The campaign has already persuaded the main airlines which fly between London and Dhakka, Bangladesh Biman and Emirate Airlines, to consider cutting rates during school holidays. The airlines carry around 70 per cent of passengers to Bangladesh.
"Extended leave" has long been recognised as a serious barrier to ethnic-minority achievement. A report by Tower Hamlets - the East London borough with the country's highest number of Bangladeshi pupils - found that the impact of extended leave was double the actual time lost.
Kamrul Ahsan, counsellor of education and politics at the Bangladesh High Commission, said: "It's a big problem, a big, big problem. Only 10 per cent of the British Bangladeshi community have professional jobs, and many have the lowest standards of living in the country. It is important to maintain cultural links, yes, but it is also important for a disadvantaged community like ours to concentrate on education."
Ninety-five per cent of pupils at Shapla primary school in Tower Hamlets are of Bangladeshi origin. Acting head John Reading said: "We understand the need to go back, and we understand that if you're taking a family away it's very expensive. For that cost and all that way, no one is going to go for a week in half-term.
"We've recently had a couple of families go for 10 weeks using the summer holidays and the first four weeks of term, which is obviously better than 10 weeks in term. But the problem isn't over when they get back. We often find even the liveliest of children are very quiet when they return, because they've forgotten their English or it takes them so long to get back into the swing of things."
Dual-language leaflets and tapes explaining the law on absence from school will be sent to schools and community groups.
A DFEE spokesman said it was possible the "joint approach" tactic may be extended to other overseas governments in future.