LONDON (AFP) - A London doctor went on trial on Monday for carrying out female genital mutilation in only the first such case to be prosecuted in Britain despite pressure from campaigners.

Dhanuson Dharmasena, 32, is accused of performing an FGM procedure on a woman who gave birth at his hospital in 2012 following damage caused by labour.

Another man, Hasan Mohamed, 41, who translated for the woman in hospital, is accused of encouraging an offence of FGM, and of aiding and abetting Dharmasena.

The woman, who was 24 at the time, first underwent FGM at the aged six in Somalia. The doctor carried out procedure again when her stitches tore during childbirth.

"It is that stitching back together by Dr Dharmasena, and Mr Mohamed's insistence or encouragement, which the prosecution says is an offence under the act," prosecutor Kate Bex told the court.

She said the procedure was "against the policy of his employer" - Whittington Hospital in north London - and that it was not "medically necessary".

Dharmasena denies the charge and has said the procedure may have been "medically justified".

About 100 million to 140 million girls and women globally are thought to have undergone FGM, which ranges from removal of the clitoris to more widespread mutilation, and can lead to infection and long-term severe pain.

FGM has been illegal in Britain since 1985 but no-one has ever been prosecuted.

There have been increasing calls on police and the government to act and last year a new requirement on British hospitals was introduced to keep a record of patients who have been subjected to FGM.

Government figures indicate that tens of thousands of women in Britain are living with the consequences of FGM.

Anti-FGM legislation was extended in 2003 to make it an offence for British nationals or permanent residents to carry out FGM abroad or seek FGM abroad, even where it is legal.

The maximum penalty is 14 years in jail.