Nurses and midwives can be suspended for deliberately misgendering patients.
Guidance from regulator the Nursing and Midwifery Council (NMC) tells clinicians how to 'express their beliefs appropriately' and when they are at risk of sanction.
The latest update includes an example where a midwife who believes the government is destroying healthcare shares her views at a dinner party.
Regulators would only take action if the obstetrician promised to treat patients differently based on their political views.
The NMC guidelines were recently highlighted in a video posted by obstetrician and NMC panelist Dr Sally Pezaro, whose help the nurse in question was 'fundamentally incorrect because it has been proven that you can change your sex and gender'.
But one more example shared in the latest update has raised concerns that sanctions could be imposed on nurses and midwives who address trans patients with the wrong pronouns.
The hypothetical scenario describes one nurse intentionally mistreating a trans patient visiting a diabetes clinic.
Despite the patient repeatedly asking the nurse to address them as the 'correct' gender, the doctor refuses to do so, resulting in a formal complaint.
When the employer then confronts the nurse about her behavior, she states that she 'acted in accordance with her belief that people cannot change their sex or gender'.
The NMC concludes that it is likely to take action against the nurse for this act, but does not specify the exact punishment.
“The persistent and deliberate abuse of a trans person is contrary to the code's requirements to treat people with kindness and respect,” the guidance reads.
'Although gender-critical beliefs are protected under the Equality Act, this does not mean that people with gender-critical beliefs can 'misgender' trans people with impunity.'
Under new UK guidelines, nurses and midwives could be penalized for misgendering patients because they believe people cannot change their biological sex (stock image)
The NMC has the power to strike nurses and midwives from its register, banning them from working in Britain.
However, this is typically only handed out for serious violations, such as when a registrant has been found guilty of heinous crimes, or has a serious lack of the necessary skills to safely care for patients.
In other cases, the NMC may temporarily suspend nurses and midwives from work or require them to be directly supervised by another professional at work.
Organizations critical of the creeping gender-neutral language in healthcare have questioned the NMC's example, framing the observation of the reality of a patient's biological sex as a 'belief'.
Stella O'Malley, psychotherapist and director of medical campaign group Genspect, said it was “extremely worrying” language that could open the NMC to legal challenges.
She told MailOnline: 'Professionals, especially those working in healthcare where misgendering a person can have catastrophic consequences, should have the right to clarify and even highlight a person's gender.
“For example, if a trans man has abdominal pain, the nurse may need to determine whether the trans man, who is biologically female, could be pregnant.”
She added that the regulator had to “protect” the freedom to clarify important medical facts to protect patients.
“While a person's gender identity may be important to some people's sense of self, their biological sex can be a matter of life and death in a hospital setting,” she said.
Ms O'Malley also slammed the NMC for treating biological sex as a 'faith'.
She said: 'The NMC is wrong to claim that it is a 'belief' that people are unable to change gender.'
'This is like saying it is a 'belief' that water is wet.
“This is a fact: no person in the history of the world has changed their gender – many have changed their gender identity, but no one has changed their sex.”
Shelley Charlesworth, spokesperson for Transgender Trend, a campaign group concerned about the sharp rise in the number of young people changing genders, also told this website she was concerned about the NMC's language.
She said: 'Nurses and midwives need to understand how male and female bodies differ and what that means for the treatment of their patients.
“They should never be punished for that knowledge, or for speaking and acting on it.”
The NMC guidelines were recently highlighted in a video posted by obstetrician and NMC panel member Dr Sally Pezaro, a professional who adjudicates in cases where nurses and midwives are sent to the regulator for possible sanction.
The midwife, who previously stated that 'not only women give birth', discussed the NMC example of the nurse who misgendered a patient on TikTok.
She said: 'They are fundamentally incorrect because it has been proven that you can change your sex and gender.'
Responding to Dr Pezaro's video, Ms Charlesworth said: 'It is deeply concerning that a panel member who sits on the board and assesses the suitability of nurses and midwives is making statements that are not based on scientific fact.'
Professor Jenny Gamble, an obstetrics expert from Coventry University, told MailOnline that the NMC guidelines themselves were not the problem and that nurses who 'deliberately and repeatedly' upset patients should obviously face investigation from the regulator.
However, she added that there was a problem with the regulator's wording of 'belief' in sex.
Critics disagree that the Nursing and Midwifery Council has published new guidance treating the observation of biological sex as a 'belief' and say the regulator should issue a clarification (stock image)
She said: 'It would be clearer and more useful if the example of the nurse who deliberately and repeatedly mistreats a person did not introduce the 'belief' about sex in addition to the comment about gender.
'There is a lot of confusion about the difference between sex, a reproductive category, gender, a social role, and gender identity, an inner sense of self. They are not synonymous.'
Professor Gamble added that the NMC may need to clarify what this means as recording patient gender was a critical safety issue.
“Accurately recording sex is a matter of safety and quality of care and not a matter of freedom of expression,” she said.
'NMC may need a position statement on the requirement to accurately record sex in all healthcare settings.
'Respectful communication is essential in healthcare and referring to individuals based on their preferences is part of respectful care, but this should not extend to inaccurately documenting a person's gender. It's too risky to do that.'
Responding to concerns, Matthew McClelland, NMC executive director of strategy and insight, said: 'From time to time people raise concerns with us about protected beliefs and freedom of expression.
'As we assess these it is very important that we take a consistent approach that reflects the law.
'The updated guidance is rooted in the law and will help our colleagues make quick and fair decisions in cases that are fit to practice.
'It makes clear that people have the right to freedom of expression and protected beliefs, but that there may be circumstances where what a nurse, midwife or nursing assistant says, and importantly how they say it, could affect their suitability to practice .'
It is impossible for humans to change gender, which is determined at conception.
In extremely rare cases, people can be born intersex, which could mean they have a combination of male and female traits.
People can change their gender identity over the course of their lives, but this does not change their gender.
Even surgery to match parts of a person's reproductive anatomy to those of the opposite sex does not overwrite biological sex.