For the first time, more young people in the UK describe themselves as bisexual than gay or lesbian combined, the figures from the Office for National Statistics show.

It is the latest evidence pointing to a shift in attitudes towards sexuality, with increasing numbers viewing their own position as somewhere on a spectrum rather than it being a black-or-white question.

A survey by YouGov published last year found that half of young people, and almost a quarter of the population overall, define themselves as something other than 100 per cent heterosexual.

The overall numbers identified by the official estimates are still very small.

Just 1.7 per cent of the population identified themselves as lesbian, gay or bisexual in the ONS's Annual Population Survey (APS) – although LGBT groups have long argued that official research, by its very nature, is likely to significantly underestimate the true level.