Up to 300 girls a year are removed from Bradford schools and flown to Pakistan for "forced" marriages, an MP claimed today.

Parents order girls as young as 12 to quit their studies and then threaten or blackmail them to live with relatives thousands of miles away where they prepare to become brides, said Keighley MP Ann Cryer.

Families can receive sums of £10,000 for their daughter's hand, she said.

Following the marriage - usually without consent - the girls return to Britain to support their new husband's visa application.

Mrs Cryer has revealed the astonishing extent of the practice at Parliament in a hard-hitting letter to Home Secretary David Blunkett, Solicitor General Harriet Harman and Children's Minister Margaret Hodge demanding action.

She is seeking changes in the British law so that aiding and abetting a forced marriage, or coercing forced marriage, becomes a crime.

She and Bradford North MP Terry Rooney said they and the other Bradford MPs were each contacted by an average of two girls a week who feared they were about to be taken out the country by their families.

Both politicians said they have dealt with dozens of harrowing cases of forced marriage in the Asian community. In one case, a girl was sent to Bangladesh at 12, married at 14 and returned to Keighley aged 16 with a two-year-old son.

Mrs Cryer said only a minority of families clung to the ancient custom of forcing daughters to marry a man - usually a first cousin - selected by parents and grandparents.

But the Labour backbencher, who has fought the problem for five years, said preventing teenage girls having an education held Asian communities back socially and economically.

She told the Telegraph & Argus: "I've been told 300 girls a year disappear from schools in the Bradford district.

"They get pressure from their parents to marry in Pakistan. They don't really have a choice. They often fear defying their families and daren't say no."

Mrs Cryer said girls aged 12 to 16 were being removed from Bradford schools.

Families found it easier to "protect their virtue" in Pakistan, away from exposure to the "corrupting" influence of friends and Western culture, such as television and music, before they are eventually married, she said.

It was also harder for teenagers to reject marriage if they were living with relatives in a foreign country.

Girls can also marry at 15 in Pakistan - although in some rural communities the age limit is ignored.

Usually the girl returns to Britain once they are 18.

Once she secures a job paying roughly £130 a week she can sponsor her newly-wed husband's visa application but that means she turns her back on education for good.

Mrs Cryer said she feared the problem will get worse.

She said: "More and more girls who are born in Bradford are reaching the age when they are seen as a highly sought after and highly-prized commodity. It is a scandal."

"Part of the tragedy is that it is self-defeating for the Asian community. If you look at it simply from the point of view of social and economic achievement, this so-called custom is holding them back.

"By abandoning their daughters' education, they are destroying the chance of young Asian girls going to college and university and getting good jobs where they can make a difference."

Action to prevent forced marriage has to be brought about through the laws on false imprisonment, threatening behaviour, harassment or assault but Mrs Cryer wants new legislation to outlaw the practice.

She said: "A new law may not stop the problem but it is worth trying. Parents will also realise what they are doing is not only un-Islamic but against the law of the country."

A Home Office spokesman said many existing laws such as assault and kidnap were already used in connection with the issue.

But he said: "We are determined to put an end to it.

"Forced marriages cannot be justified on any ground, religious or cultural. We are working to raise awareness on the issue."

A spokesman for Women's Minister Jacqui Smith said talks were needed between parents, children and opinion formers, such as MPs and councillors, in communities affected by these problems.

"We need to change attitudes to prevent the all too sad ramifications of forced marriages," he said.

"It is also important young girls realise that if they find themselves in this position then there are always people they can to turn to for help."

An Education Bradford spokesman said no figures were available for the number of girls that were taken out of the district's schools.

Its principal education social worker, Barbara Lawrie, said children were allowed two weeks authorised absence from school then a further two weeks unauthorised before they were removed from a school roll.

If they do not return when they have stated then an investigation was started into the child's whereabouts. If they were in this country then the parent had to ensure they attended school.

But she said: "Parents can decide if they do not want their child to finish their education in this country."

The President of the Bradford Council of Mosques, Sher Azam, said he was aware that some forced marriages were taking place.

He also pointed out they were illegal in Pakistan and India and he was surprised there was not a specific law against them in this country.

"I am surprised there is not a law against it already," he said. "Choosing who you marry is a basic human right of the individual either male or female.

"Children should be allowed to enjoy their childhood. If there are so many leaving their schools it is very sad and Mrs Cryer is doing the right thing.

"No faith or religion condones it and it must be stopped.