They said the current law, which allows marriage at 16 with parental consent, sabotaged girls' futures and condoned child abuse.

The loophole also undermines Britain's global efforts to end child marriage in other countries, campaign groups said.

"Child marriage is child abuse," former chancellor Sajid Javid told BBC radio before presenting the bill, which has cross-party support.

"People think this is often something that just happens in developing countries. It doesn't. It's happening right here ... it has to stop," he said, adding that thousands of minors had been coerced into marriages in Britain in the last decade.

The government has also said it is committed to lifting the minimum age to 18.

"It's a big step in the right direction. We're celebrating this moment," campaigner Payzee Mahmod told the Thomson Reuters Foundation.

Girls from South Asian and Middle Eastern backgrounds are seen as most at risk of early marriage in Britain because having relationships outside marriage is often considered shameful.

Britain set 16 as the minimum age in 1929 when living together out of wedlock was socially unacceptable.

But campaigners say most girls who marry under 18 nowadays are pressured into it by their families, and that raising the minimum age would empower them to say no.

Parliamentarian Pauline Latham, one of the bill's sponsors, said the current law permitted child marriage "by the back door".

"I've spoken to a lot of ministers to say we cannot let this continue, and they've agreed. Boris is keen to get it through," she added, referring to the prime minister.

An attempt to amend the law last year - spearheaded by Latham - was derailed by the pandemic.

But campaigners said they were confident the legislation, which applies to England and Wales, would pass by next spring.

More than 2740 under-18s were married in England and Wales between 2008 and 2017, according to official data, but this figure excludes minors wed in traditional ceremonies or taken abroad to marry.

Australian Associated Press