One of Britain's most successful cyclists has publicly disclosed a change in gender and identity - after previously staying private because of the "archaic views and prejudice" of "certain sections of the tabloid media".

The rider formerly known as Robert Millar said she was happy to announce she had "transitioned" to Philippa York as 2017 is a time of "much better acceptance and understanding".

Then-Millar was crowned the Tour de France's prestigious King of the Mountains, effectively the race's best climber, in 1984.

The fourth place finish that year remained the highest achieved by a British rider until the recent Tour wins by Sir Bradley Wiggins and Chris Froome.

Philippa York, then Robert Millar, seen cycling in the Tour de France in 1990. Credit: PA

Writing on cyclingnews.com, she said: "As much as I've guarded my privacy over the years there are a few, I believe obvious, reasons to why I haven't had a public 'image' since I transitioned.

"Gratifyingly, times have moved on from 10 years ago when my family, friends and I were subjected to the archaic views and prejudice that some people and certain sections of the tabloid media held.

"Thankfully gender issues are no longer a subject of such ignorance and intolerance, there's a much better acceptance and understanding."

Her statement came as ITV announced she will be part of the Tour de France commentary team from July 13 for three days, stages 12 to 14.

York said she was pleased to return to a more "active role" in the sport.

The rider enjoyed three Tour de France stage victories and consecutive second placed finishes at the Vuelta a Espana. Credit: PA

"I really am delighted to have accepted this new challenge with ITV4," she said.

"I'm looking forward to the racing immensely and in terms of my personal and professional development I think this is the right time to return to a more active role in cycling too - the sport I've always loved."

The cyclist, who was born in Glasgow in September 1958, won three stages of the Tour.

The rider finished second in the 1985 and 1986 Vuelta a Espana and the 1987 Giro d'Italia.

Writing in the Guardian, York added: "I've known I was different since I was five years old, [but] what that difference was and how to deal with it has taken a fairly long time to come to terms with. All I will say is it hasn't been an overnight process.

"Sport has generally lagged behind in its attitudes to anything other than the heterosexual norm. In that context cycling has been one of the sports most resistant to change.

"It'll catch up eventually."