Tennis star Martina Navratilova has claimed transgender women in sport are 'cheating' unless they have irreversible surgery to change their anatomy.

The nine-times Wimbledon champion, 62, says she is happy to address transgender athletes by whichever pronoun they desire, but would not be happy to compete against them unless they have fully transitioned.

This is the second time Navratilova has spoken out on the subject, following a furious Twitter row with transgender female cycling champion Rachel McKinnon at the end of last year.

Writing in the Sunday Times today, she said: 'To put my argument at its most basic: a man can decide to be female, take hormones if required by whatever sporting organisation, win everything in sight and perhaps earn a small fortune, and then reverse his decision and go back to making babies. It's insane and it's cheating.'

Martina Navratilova (pictured in LA in October) has claimed transgender women competing in sport have an unfair advantage over other women unless they have had surgery

Navratilova sparked outrage last year when she got into a Twitter spat with Rachel McKinnon (pictured), 35, the only transgender woman to have won a world female cycling title

She makes a 'critical distinction' between transgender women like McKinnon who take hormones and former tennis player Renee Richards who was born Richard Raskind and had gender reassignment surgery.

Navratilova says she supports Caster Semenya, the intersex South African runner born a woman but with naturally high testosterone levels.

Pictured: Canadian academic and trans cycling champion Dr Rachel McKinnon

Semenya is this week launching legal action against the International Association of Athletics Federation (IAAF), claiming their new rules that women with high 'male' hormones' should take medication that lowers them are discriminatory.

Czech-born Navratilova has campaigned widely for LGBT rights after coming out as a lesbian in 1981 and being faced with mass homophobic abuse.

But in an opinion piece for the newspaper today she hits out at the 'tyranny' of trans activists who she claims denounces anyone who argues against them.

The tennis coach says even if transgender women have hormone therapy, they still have stronger muscles and bones and have higher levels of oxygen-carrying red blood cells from childhood.

Her first attack on 'trans tyranny' came in December 2018 when she wrote on Twitter: 'You can't proclaim yourself a female and be able to compete against women.'

She was called out by Canadian academic, who is the first transgender woman to win a female world cycling title.

Czech-born Navratilova (pictured in Florida in December) has campaigned widely for LGBT rights after coming out as a lesbian in 1981 and being faced with mass homophobic abuse

McKinnon, 35, still has her male anatomy, but has lived as a woman since she was 29.

She accused Navratilova of transphobia and demanded an apology.

The cyclist wrote afterwards: 'I still can't believe she said this...to me of all people.'

The International Olympic Committee, Rugby Football Union and British Cycling are among the sporting bodies reviewing their policies on transgender athletes over concerns they may have an unfair advantage.