Liberal Judaism and its senior Rabbi Danny Rich have backed a controversial transgender rights charity that campaigns for children to be able to receive prohibited gender reassignment treatment.

The Mermaids charity was this week awarded a £500,000 grant by the national lottery – which angered MPs and women’s organisations.

The charity has been accused of bullying, promoting falsehoods and using “emotional blackmail” to pressure parents into following its advice.

One MP told The Sunday Times he was "absolutely horrified" at the grant, adding Mermaids' work was "utterly wrong".

But on Wednesday Liberal Judaism tweeted: "Following recent events, Liberal Judaism would like to express our support for Mermaids.

“Mermaids is a charity that provides vital services supporting young trans and gender nonconforming people, and their families, to achieve a happier life in the face of great adversity.

“We stand with Mermaids and we are committed to continuing our own work towards equality and inclusion, whilst celebrating the LGBTQI+ community in all its diversity.”

Liberal Judaism leader Rabbi Rich echoed these sentiments, tweeting simply: “We stand with Mermaids.”

The chief executive of Mermaids, Susie Green, took her child for a now illegal gender reassignment operation in Thailand when they were 16, has said medical intervention is “absolutely vital” for children unhappy with their biological sex.

Her view is disputed by NHS gender specialists who say intervention is not always right.

The group also wants to overturn an NHS ban on children under 16 being treated with hormones, which can cause permanent biological changes and compromise fertility.

In October, Laura Janner-Klausner,  the senior rabbi to Reform Judaism, had revealed her child is transgender.

Rabbi Daniel Roselaar, a United Synagogue Rabbi,  addressed the status of transgender people in Jewish law in a recent lecture at the London School of Jewish Studies.

He said it mattered little where they sat in an Orthodox shul saying: “I don’t think we need to give that person more tzores (trouble) in their life to turn that into a big issue.”