A father has attacked a controversial transgender children’s charity for ‘meddling’ in a dispute over whether his five-year-old son should wear a dress to school.

The man is in a bitter battle with his ex-wife, who believes the boy identifies as a girl.

The mother believes the boy should wear a girl’s uniform to school, and is being supported by transgender children’s charity Mermaids.

But the father claims his son has simply been confused by his mother – who has been dressing him as a girl since he was two-and-a-half.

Parents in bitter battle over their child's gender: Father brands controversial transgender charity as ‘meddlers’ in yet another case of a mother dressing her son, five, as a girl

He says his son shows no desire to dress as a girl when with him, and is too young to understand the meaning of gender.

He claims the boy’s school has been ‘bullied’ by Mermaids into supporting the mother’s wish that he should wear a dress.

Mermaids allegedly told school staff they would be guilty of discrimination if they did not let the boy wear a girl’s uniform – something the father claims left the school feeling intimidated.

The incident raises new questions about the charity – which has advised schools, the NHS and the Crown Prosecution Service on transgender issues – even though it has no official status and was started by a group of parents in 1995.

Last week it emerged that Mermaids had been supporting a mother who was found to have caused her son ‘significant emotional harm’ by forcing him to live as a girl.

She had the boy removed from her care by a judge after he found there was ‘no independent or supportive evidence’ that the seven-year-old wanted to be a girl.

He said the boy, who now lives with his father, had been ‘pressed into a gender identification that had far more to do with his mother’s needs’ than his own.

And the judge condemned social workers for failing to challenge the mother because they were in thrall to ‘transgender equality’.

Mermaids described the ruling as ‘a huge injustice’.

In the case of the five-year-old, the charity is thought to have been involved with the mother for some time before intervening over his uniform.

The father said: ‘The school, at the beginning, were quite firm [with his ex-wife]. But then she started getting Mermaids involved.

'The school backed down completely.’

He said the school had been ‘scared’ by the suggestions of discrimination. He accused the charity of ‘meddling in something which has nothing to do with them’ and said it had ‘bullied the school’.

The father, 39, who works in logistics, says his son – who cannot be named – does not express any desire to dress as a girl or play with girls’ toys when he spends the weekends with him and his new wife.

But his ex-wife – who has been dressing the boy as a girl since he was a toddler – took him to see psychoanalyst Michelle Bridgman when he was four.

Miss Bridgman, who is linked to Mermaids and has no clinical qualifications, said the boy was suffering from gender dysphoria.

Father says his son shows no desire to dress as a girl when with him, and is too young to understand the meaning of gender (file photo)

The father said: ‘If my son does decide he wants to be a girl, then that is fine by me – I am not old-fashioned, that doesn’t bother me. But at the moment, it just feels like it isn’t his decision.’

He believes that the authorities, including social workers, are too scared to intervene for fear of being accused of discrimination by the vocal transgender lobby.

‘The headmaster now won’t even talk to me. They are all terrified,’ he said.

‘My ex-wife just repeats what Mermaids are saying without much real understanding of the consequences. All Mermaids are is a support group with no medical training.’

The mother confirmed Mermaids called the school on her behalf to ‘gently remind them of the law’.

She said social services had investigated her ex-husband’s complaints and found nothing wrong.

Her son ‘wears a mix of boys’ and girls’ clothes – it’s his choice’, she said.

The council, in the Midlands, declined to comment.

Caroline Roberts, chairman of Mermaids, said the charity ‘provides information and resources for families and professionals in an area that is largely misunderstood’.

Miss Bridgman said she was upset by the father’s criticisms. She said the boy’s gender dysphoria ‘is not a clinical diagnosis but an observation’.

She said she did not recommend treatment or a permanent change of gender, and would never do so in a child so young.

The 'expert' backed by the NHS...and councils

One of its most vocal figures is its CEO Susie Green, who contacted Mermaids after her child told her that he believed he should have been born a girl

It is promoted by the NHS and councils, runs workshops for teachers and claims to have provided training for police and social services.

But it is far from clear what, if any, professional credentials Mermaids has.

The organisation – which has received lottery funding – began in 1995 as a support group for parents of children affected by gender identity issues.

Mermaids became a registered charity only last year – with its documents stating that as well as supporting families, it aimed to ‘engage and lobby media and medical institutions’. But it does not appear to have any professional or clinical expertise in the area of child and adolescent mental health.

One of its most vocal figures is its CEO Susie Green, who contacted Mermaids after her child told her that he believed he should have been born a girl.

She says her daughter is now ‘a happy and confident young woman’ having taken hormone blocking medication from the age of 13.

It is not thought that Miss Green has any professional qualifications in the field but that hasn’t stopped her from instructing schools on how they should support ‘trans’ children.

She has spoken in the past of trying to encourage schools to help children to ‘transition’ – including children as young as four.

She said some schools ‘are very reluctant’ but that ‘about half’ are ‘accommodating and want to learn’.

The NHS provides a link to Mermaids on its NHS Choices website – saying the charity can ‘provide support’ and put people in touch with other parents with ‘similar experiences’.

The Crown Prosecution Service took direction from Mermaids when developing its transgender policies and the charity’s helpline has been included on cards it produced for pupils as part of its lesbian, gay, bisexual and transgender hate crime project in schools.

A number of councils have allowed Mermaids to help shape policies.

The charity is also linked to Harley Street psychotherapist Michelle Bridgman, who specialises in gender dysphoria in children. Miss Bridgman, 68, who is herself transgender, claims to see between four and seven children a week with ‘gender identity challenges’.

She said that Mermaids never sends people to her ‘directly’, adding: ‘I am not a medical clinician and do not recommend medical treatments.’

Caroline Roberts, chairman of Mermaids, said the charity had won a number of awards for its work.