Official documents, such as passports and driving licences, should be 'gender-neutral' and not say if the holder is male or female, Conservative MP Maria Miller has said.
Ms Miller, who chairs the women and equalities committee, added that a person's sex is "not relevant" on official documents and the issue causes "problems" for transgender people.
Her comments came during an inquiry by the committee into transgender equality.
In an interview with the Times (£) Ms Miller said the Government should "strip back" talking about gender unless it was necessary.
Figures from NHS England show that there are around 4,500 new referrals to gender identity services each year.
Last year the number of children aged 10 or under referred to the NHS to help deal with transgender feelings had more than quadrupled compared to the previous six years.