More than 20 organisations have signed a letter to the Prime Minister, Boris Johnson insisting current forced marriage law does not go far enough in protecting young people, The Guardian reported.

Furthermore, there is no legal provision across the UK to prevent religious or customary child marriages from taking place – at any age.

In a letter to Johnson, four co-chairs of the Girls Not Brides UK partnership wrote, “Child marriage is often viewed as a ‘developing world issue’ and one that exclusively takes place overseas. The reality is that child marriage is an invisible but thriving issue in the UK today.”

They include Diana Nammi, founder of the Iranian and Kurdish Women’s Rights Organisation, who told the Guardian, “Too often under the current inadequate law we see failures by safeguarding professionals and the consequences of child marriage, which disproportionately affect a greater number of girls, usually married to older men.”

“The impacts include reduced education and employment opportunities, an increase in mental health problems and a higher incidence of domestic violence,” she said.

Payzee Mahmod was a British child bride betrothed in 2003 to a man nearly twice her age. Her sister Banaz, who was married at 17 five months earlier, was murdered in a so-called “honour killing” at the age of 20 after she left the husband her family had chosen for her.

Mahmod, who has called for a ban on child marriage in the UK, said young people should be free to focus on their education and pursue their dreams.

She said, “Child marriage is a hidden crime, yet it is very much a live issue here in Britain and one of the most harmful things any child can go through. Girls are raped on their wedding nights by older men and it is common for them to have forced pregnancies – something my sister and I both experienced.”

“Given this issue has now been brought directly to the prime minister’s attention there should be no ‘ifs’ or ‘buts’ – it is a straightforward safeguarding issue,” she added.

During lockdown the campaigner was contacted on social media by girls at risk of child marriage seeking help – the youngest was just 14.

They had seen Mahmod’s Tedx talk on child marriage. Mahmod is concerned the pandemic may have put more children at risk.

“Girls have been out of school for so long and it’s really scary to think how many might have fallen under the radar without the oversight of teachers and other professionals,” she said.

Under laws dating back to before the second world war it remains legal for 16- and 17-year-olds to register a marriage with parental consent. But this loophole leaves them more vulnerable to grooming and coercion, campaigners argue. In Scotland, the legal age is 16 and no parental consent is needed.

The letter from frontline organisations working to protect women and children explained, “Existing forced marriage law does not automatically protect children from child marriage on account of their age.”

“Unacceptably the onus is on the child to secure their own protection under forced marriage law by speaking out against their own family and community which can have dangerous consequences and [which] understandably many children are too terrified to do,” it added.

Javed Khan, chief executive of Barnardo’s said, “The government has rightly committed to all children being in education until the age of 18. But we now need safeguards to prevent coerced marriages for under-18s, to protect their childhoods, their futures and in some cases, their lives.”

The children’s charity has signed the letter along with other groups including Karma Nirvana, the Muslim Women’s Network UK, and SafeLives.

They said that UK law undermines the government’s efforts to end child marriage overseas and has set a precedent that has seen Bangladesh lower its minimum age of marriage from 18 with parental consent.

Bangladeshi officials have cited England and Wales as hypocritical for trying to engender progressive change abroad while turning a blind eye to child marriage at home, said the letter.

The latest data from the government’s Forced Marriage Unit shows more than a quarter of cases (363) involved children aged under 18.

Nirvana, which runs a national helpline supporting the victims of “honour” abuse and forced marriage, said it had responded to 1,041 contacts on child marriage since 2015, some involving children as young as 11.

Pauline Latham MP, who is championing a bill to make child marriage a crime, has written separately to the prime minister ahead of the Queen’s speech next week.