Parents will face prosecution if they fail to stop their daughters undergoing female genital mutilation (FGM) under new measures being announced.

Prime Minister David Cameron is unveiling a £1.4m prevention programme aimed at ending the practice at a global summit in London.

It is estimated that up to 137,000 women and girls living in England and Wales could have undergone FGM.

The Girl Summit will also look at ways to end forced marriage.

Hosted by the UK government and children's charity Unicef, the summit will be attended by international politicians, campaigners including the Pakistani teenager Malala Yousafzai, and women who have undergone FGM.

Speaking ahead of the conference, Mr Cameron said: "All girls have the right to live free from violence and coercion, without being forced into marriage or the lifelong physical and psychological effects of female genital mutilation.

"Abhorrent practices like these, no matter how deeply rooted in societies, violate the rights of girls and women across the world, including here in the UK."

'Big challenge'

The FGM prevention programme will see the NHS working with girls affected by the practice.

Phumzile Mlambo-Ngcuka, the executive director of UN Women, said the situation is improving but many girls remain at risk.

She said: "There's traction and more people that are willing to take a stand, but not enough yet.

"The fact that 30 million girls are at risk of being cut in the coming years clearly means that we have a big challenge on our hands."

Priscilla Karim, who was forced to undergo FGM in Sierra Leone aged nine, described her ordeal.

She said: "I felt the worst pain of my life and a heavy object sitting on my chest and I just passed out.

"It's like a taboo, they don't tell you about it. You cannot tell anybody.

"I grew up with the fear that if I say to anyone, I was going to die because that was what they made me believe - that whatever happens there is kind of a secret."

It has been illegal in Britain since 1985, but the first prosecutions - which are currently ongoing - were not until this year.

Other FGM measures include:

Training for teachers, doctors and social workers to identify and help girls at risk Lifelong anonymity for victims New guidance for police on handling FGM cases An "international charter" calling for the eradication of FGM and forced marriage within a generation will also be unveiled, along with programmes to identify child and forced marriage in 12 developing countries.

Home Secretary Theresa May, Deputy Prime Minister Nick Clegg and Justine Greening, the international development secretary, will also appear at the summit.

Mrs May said: "FGM and forced marriage are incredibly harmful practices, and it is terrible to think about the number of women and girls in the UK who have been subjected to these crimes."

MPs recently said the UK's failure to tackle FGM was a "national scandal", and that failures by ministers, police and other agencies had led to the "preventable mutilation of thousands of girls".

Unicef said its research showed that more than 130 million girls and women had experienced some form of FGM in the 29 countries in Africa and the Middle East where it is most common.

It also said 250 million women and girls alive today were married before the age of 15.

Unicef executive director Anthony Lake said: "The numbers tell us we must accelerate our efforts."