He also feared that staff and governors had been misled by the transgender lobby group Mermaids, which had been invited in to advise the school.

After his worries were dismissed by the bishop, Mr Parker quit the church where he had been a vicar for 14 years, and also the school after seven years as governor.

In an emotive resignation letter to his bishop, Mr Parker wrote of his fear that children were being 'sacrificed on the altar of trans ideology', even in Church schools.

Mr Parker said last night: 'I was basically told by my bishop that if I wished to faithfully follow the teachings of the Bible then I was no longer welcome in the Church. It felt very much like I was being silenced by the Church and the school.'

The dispute comes amid growing controversy over the number of children now choosing to change gender.

Mr Parker, 49, was told in March that an eight-year-old pupil would be transitioning from a boy to a girl at the primary school in an Essex village. The Mail on Sunday is not naming the school to protect the privacy of the pupils.

He raised concerns that the school had no formal policy on how staff should deal with a child who wanted to change gender.

There was no guidance to cover matters such as whether the student would be allowed to use the girls' toilets or share changing rooms and accommodation with female pupils during trips away.

Mr Parker was equally keen to receive assurances that other pupils and parents would be told about the student's transition so they could be prepared.

He asked for evidence that the child had seen a psychologist or a medical professional to ensure that the desire to live as a girl was not being driven by the parents -- but his request was dismissed.

The vicar also questioned whether any 'pastoral provisions' had been made for Christian parents and children who might be confused about what was going on at the school.

But Mr Parker said when he put these points to the head teacher at a meeting, she dismissed them as merely being his 'personal views'.

He said she told him she was legally bound by the Equality Act not to deviate from the way she was already handling the transition, and that parents would not be informed about what was happening.

Mr Parker said: 'After the head told us about the plan to allow the pupil to transition, the school suddenly turned into a place where you did not even have the freedom to question things. I felt it was no longer a Christian place of grace and truth -- it was a place of oppression.'

But the most disturbing episode for the softly spoken clergyman was yet to come. In April, the transgender youth charity and campaign group Mermaids was invited into the school to deliver a training session to teachers and governors.

According to Mr Parker, the head said she had brought in the group on the advice of the diocese and the local authority.

Mermaids has previously attracted criticism for advocating the prescription of sex-change hormones to youngsters under 16.

During a two-hour presentation, the Mermaids trainer, who said she had a 'background in education', instructed the group on a range of complex subjects including neurology, biology of the sexes, transgender mental health and equality laws.

She insisted it would be illegal to deny anyone the use of the toilets or changing rooms for the gender they identify as, and warned using the wrong pronoun for a transgender child would be a 'hate crime'.

Many of the points made in the lecture -- including sections on the science of biological sex -- were simply wrong, contends Mr Parker, who studied biology at Oxford.

At the end of the session, which was recorded by Mr Parker, those who attended were told they could ask questions.

But when the vicar politely attempted to query what he considered to be legal and scientific falsehoods, he was aggressively shut down.

'The presentation was so full of factual inaccuracies,' he said. 'I am an Oxford biologist by background so I was gobsmacked by what was being said from a biological perspective.

'I also knew some of the legalities of the situation and knew that the whole governing body and staff were being misled.'

After gently requesting if he could pass on some literature to staff which contained 'alternative' factual information, he received the sharp reply from the head teacher: 'No, I don't think so, John. It's training today, it's not time to share your viewpoints.'

When he vainly tried to defend himself by saying that it was not an opinion he wanted to share but scientific facts, he was again abruptly cut off by the head teacher.

The Mermaids instructor barked: 'My job is to deliver training. I have done that. I don't have to listen.'

The vicar was so shaken by the tense exchange that he broke down in tears afterwards.

'From a Christian point of view, it went against everything, not just in terms of speaking the truth, but also allowing freedom of speech and freedom of discussion and disagreement.'

Mr Parker said this upsetting incident was the final straw and followed his increasing disillusionment with the Church of England's 'unquestioning acceptance of a particular kind of politically correct transgender ideology'.

Last December, the Church issued new pastoral guidance encouraging ministers to create new baptism-style ceremonies for transgender people.

'I have felt growing disquiet about the intolerance to holding different views within the Church,' he said. 'But when I raised my worries with bishops about the direction the Church was moving, I was told that if I didn't accept their approach, I could leave.'

At the end of April, Mr Parker informed the primary school that he would be resigning as governor with immediate effect.

Shortly after this, he informed the Bishop of Chelmsford by letter of his decision to resign as a vicar, concluding 'there is no longer a place for me in the Church of England'.

The school eventually decided to email parents on the day of the pupil's transition to let them know what was happening.

Andrea Williams, of the Christian Legal Centre, said: 'This is not an isolated case and we are going to see more like it if nothing is done.

'Parents have a right to know if and when this ideological movement is in their schools and being taught as fact.

'I believe a real threat is posed to schools from organisations such as Mermaids. They implement a new ideological tyranny -- and any disagreement is at best silenced, and at worst, punished.

The number of children confused about their sex and gender and seeking treatment is escalating and it is our children who are suffering. In imposing this ideology, we are not being kind but cruel. It is time for this to stop.

'The Church of England has one million children in its care. This is a serious God-given duty which the Church is failing at.

'It has invited the new state ideology into the classroom and it has lost confidence in its own message of what it means to be human. The Church needs to act before it is too late.'

Last night, a former parishioner of Mr Parker's spoke of his sorrow at the vicar's resignation: 'I've been coming to this church for six years. John has been brilliant. He will be missed.

'People really like him for what he's done over the years. He's well respected, and he's respectable. There's no way you could say that he's a bigot.

'He always makes an effort to see people, to connect with people, whether or not they go to church. You don't need to come to church -- he's there for you.'

The Rev Tim Elbourne, director of education for the Diocese of Chelmsford, said: 'Church of England schools are inclusive environments which nurture pupils to respect diversity of all kinds.

'Our schools must comply with the legal requirements of the Equalities Act 2010. Additionally, the Church of England, through its policy Valuing All God's Children, gives guidance for Church of England schools.'

A spokesman for the school said: 'We understand the concerns and convictions of the people on our governing body and we are very sorry he has left us.

'We respect that everyone will have their own opinions regarding transgender pupils and how a sensitive issue should be managed and communicated.

'We have embarked on a process of communication surrounding the rights of transgender pupils and input from outside the school has been carefully managed.

'As a Church school, we believe that if we have disagreements around personal choice and individual rights, that these are managed respectfully.'

END