Britain’s National Lottery is awarding a giant cash sum to a child sex change “charity” accused of using intimidation and blackmail to promote fertility-compromising “treatments” for underage children.

Led by IT consultant Susie Green, who put her son on estrogen at the age of 13 and went to Thailand to give him sex change surgery at the age of 16, Mermaids claims that irreversible medical treatment is “absolutely vital” for children who believe they were “born in the wrong body”.

However, Green — who has been promoted in the media as an expert on “trans kids” and invited to give evidence to MPs and speak at various conferences including the Westminster Social Policy Forum — and her “militant” organisation have been accused of silencing critics, advertising cross-hormone treatment banned on the NHS, and lying about suicide statistics to boost their cause.

Twitter Transgender Critic ‘Questioned by Police and Banned from Leaving UK’ https://t.co/DjLq8gqlwd — Breitbart London (@BreitbartLondon) April 5, 2018

Conservative MP David Davies has joined feminist groups in calling for Mermaids’ £500,000 lottery grant to be halted pending an investigation into the decision, according to the Sunday Times.

“I am absolutely horrified that the Big Lottery Fund are handing out a fortune to this aggressive organisation,” the Monmouth MP told the newspaper. “What they are doing is utterly wrong.”

The Big Lottery Fund, a public body led by the former Tory MP Peter Ainsworth, said: “We are in the process of awarding [Mermaids] £500,000 over five years to increase localised support. If concerns are raised we will always look into them. However, we do not see any reason not to fund this.”

Mermaids will use the money to expand its work nationwide with a network of 45 new groups, according to Times senior correspondent Andrew Gilligan, who detailed in his piece some of the charges against Green and her organisation, including their war on medical experts who have urged caution regarding rushing children into life-changing sex change treatment.

In evidence to MPs, Mermaids

– attack a Dr at the NHS gender clinic by name

– urge "a thorough audit of staff & their views"

– attack it for speaking of "uncertainty and complexity" and "misinterpreting" medical evidence.

Your regular reminder: Susie Green is an IT consultant. — Andrew Gilligan (@mragilligan) December 16, 2018

In addition to the group’s campaign to abolish NHS restrictions on treating children under 16 with cross-sex hormones, Mermaids recommends on its website that parents wanting to evade the evidence-based age barrier contact Gender GP.

Gender GP operator Helen Webberley was criminally convicted of illegally providing medical services and fined £14,000 earlier this month for having continued to operate a private clinic, from which she gave out hormone treatment to children as young as 12, after the regulator refused her a licence.

Mermaids, which has received hundreds of thousands of pounds from taxpayers over the years, was also ordered not to contact a family after a judge ruled a woman, who was being advised by the group, had been abusing her seven-year-old son by forcing him to live as a girl.

In a High Court case reported in 2016, Mr Justice Hayden ordered the boy be removed from his mother, who the judge found had caused “significant emotional harm” to the child and “pressed [him] into a gender identification that had far more to do with his mother’s needs and little, if anything, to do with his own”.

Prince Harry calls transgender children’s charity @Mermaids_Gender ‘amazing’ at Buckingham Palace event https://t.co/okzpJmpg8s — PinkNews (@PinkNews) October 11, 2017

The Big Lottery Fund now claims it will undertake a review of the grant, in response to what is describes as a “range of correspondence”.