Four Birmingham schools have been accused of "condoning failure" by allowing pupils to take an extra month's holiday each year.
The extended vacation entitlement at the schools, all in Sparkhill, is intended to recognise the need of parents in the multi-ethnic area to visit family in their country of origin.
Those who take advantage of it are encouraged to add the additional days absence to existing holiday times.
All four of the schools involved in the partnership scheme are primaries - Greet, Arden, English Martyrs and St John's.
Sparkhill's population is predominantly Muslim with the majority of families originating from Pakistan.
Many have strong links with their country of origin and are keen for their children to visit relatives abroad.
Pat Smart, headteacher of Greet Primary School in Percy Road, defended the decision to allow pupils to skip up to 20 days during term time.
She said: "By managing that long-term absence we get the understanding and respect of the community.
"We understand that the links with home are very important for them. Many of the children gain a lot from visiting their extended family."
Truancy has been a cause of growing concern among education chiefs. Figures from the Department for Education and Skills show Birmingham has more truancy than anywhere else in the country apart from London.
Nearly a third of secondary school pupils and a quarter of primary-age children played truant in the city in 2003/04.
Education bosses have been keen to highlight the damage to learning of pupils missing even a few days from the classroom.
Brenda Bullock, who has been teaching in Birmingham for 40 years, claimed the extended holiday scheme damaged the education of already disadvantaged pupils.
"The fact that they are an ethnic minority and speak another language at home means they need all the time in school they can get.
"By taking them away they are harming their chance of success at school. I think allowing parents to take them out is condoning failure for the children," she said.
Greet Primary has appointed a "home link worker" to negotiate with parents the best time for them to take an extended holiday.
Pupils visiting relatives abroad outside the normal 14-week vacation entitlement are registered as authorised absences.
Education chiefs in Birmingham have raised concerns over increasing numbers of parents taking their children on holiday during term time to take advantage of cheaper deals.
Before Christmas the city's head of education welfare John Smail highlighted the dangers of skipping even one or two days from school.
Last night he said: "The city council is very clear in its advice; parents should not normally take pupils on holiday during school term time.
"We do understand that schools need to be sensitive to exceptional requests including those from families who wish to maintain links with their home country."