Passports and driving licences should not state if the holder is male or female because it causes "problems" for transgender people, a Tory MP has said.

Maria Miller, chair of the Commons Women and Equalities committee, said a person's sex was "not relevant" on official documents, and it created an "unconscious bias" in job applications.

Gender details on passports also do not assist with identification, she added.

The committee will publish a report on transgender discrimination next week.

In an interview with the Times newspaper, Ms Miller said gender stereotyping can be as "damaging" for men as women.

"For individuals who have decided to transition but haven't necessarily got the right documentation, it can cause problems," she said.

'Frankly ridiculous'

"Why do we need gender on our driving licence? Why do we have to have it on our passport if it doesn't really aid identification? It's not relevant.

"Australia has decided to degender their passports."

Liberal Democrat leader Tim Farron said his party had pushed for the change during the coalition government's term in office.

"This is not as radical an idea as it might seem - other countries like Australia have already introduced it and it is accepted by the International Civil Aviation Organisation.

"It is frankly ridiculous that even on something this small the Tories have refused to act over the last few years."