Forced marriage is not confined to Britain’s Muslim communities but exists among all minority groups, the head of a commission into the issue has said.

Baroness Butler-Sloss said there was “a great deal of pressure” on parents and elders to ensure that children married within their strongly religious communities.

The former High Court judge, who chairs the National Commission on Forced Marriage, said that there was “a thin line” between legitimate emotional pressure and coercion.

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“We have discovered that it is not exclusively a Muslim issue. It is an issue that affects other minority communities for instance Sikhs, Hindus, Orthodox Jews and indeed any group that values the tight-knit community of which it is part and is very concerned that members of that community should not marry outside the community,” she told the UK’s first national conference on forced marriage in Derby.

Forced marriage is set to become a crime in England and Wales from next month punishable by up to seven years in prison. The change in the law follows public outrage over the treatment of young women such as Shafilea Ahmed, 17, who was murdered by her parents in front of her siblings in 2003 and had her body hidden after she drank bleach in a bid to avoid being forced into marriage. Her parents were not brought to justice until 2012.

Last year more than 1,300 people rang a special helpline set up by the Government’s Forced Marriage Unit. Around one in seven of those reporting actual or potential forced marriage were children. A quarter of callers were aged between 16-17, figures showed.

Senior police officers believe this represents the tip of the iceberg with forced marriage linked to serious honour based crime including abduction, rape, torture and disfigurement.

However, figures showed that 42.7 per cent of those contacting the helpline were of Pakistani heritage whilst 10.9 per cent were from India and 9.8 per cent from Bangladesh.

Commission member Jasvinder Sanghera, a Sikh survivor of forced marriage who founded the charity Karma Nirvana, said it was “not helpful” to focus on Muslim communities although the problem remained “disproportionately” reported among those groups.

“There are not enough community leaders – Muslim, Indian or Sikh – speaking out on this issue,” she said. Ms Sanghera said the commission, which is due to report next year after speaking with survivors of forced marriage across the UK, had noticed wide variation in the public response to victims. ”The evidence is showing inconsistencies in reporting and responses from police, social workers, schools and politically,” she said.

Some police forces and other professionals have tried and negotiate between victims and their families, often putting girls and women at risk of harm.

Prime Minister David Cameron will host a summit on female genital mutilation and forced marriage later this summer. Campaigners are seeking to mark Shafilea Ahmed’s birthday on 14 July as a national memorial day marking the deaths of the victims of honour violence.

More than 30,000 people have signed a petition urging Mr Cameron to support the proposal. The idea received the backing of Nazir Afzal, chief of the Crown Prosecution Service in the North West, who reopened the case into Shafilea’s murder.

“The idea is that when people do what they have done in this case is that they are trying to erase the girl from history. The family will never want to know her – the family don’t want to know she existed. Therefore having a memorial day sends out a message: We remember, we remember her life, we remember why she died and why she didn’t have to die,” he said.