THE tennis queen's next big match will be played in a law court when she attempts to defend homosexual rights in her home state of Colorado. CHRIS Evert found the diversion of a family and so took her leave of the tennis courts. John McEnroe is now having his impending departure from tennis hastened by family concerns. Jimmy Connors has nothing better to do with his time, so he remains even inhis 40s. But . . . Martina Navratilova? She has long discussed the day she will call an end to her fabulous tennis career. Retirements were contemplated after tearful exits at the 1990 and 1992 US Opens, but what to do? If ever there is proof that with one door closing, another opens, it will come with 36-year-old Navratilova, winner of a record nine Wimbledon single's titles, a record 161 single's championships and, for good measure, another 160 double's titles. She is about to take her bow as champion of the tennis courts to become champion of unpopular causes, as an activist concerned with human rights. Today her campaign is against a referendum - Amendment 2 - passed in her US home state of Colorado where 53 per cent of the state's voters agreed with a constitutional reform to deprive homosexuals of any legal standing should they argue they were victims of discrimination, say in a job application, because of their sexual preferences. It is a battle that has ensured she has no idle time in her Colorado Rockies retreat to reconsider her decision to make 1993 her last year for playing singles. December was once her month away from tennis and the public, but this December was spent seeking as much public attention as possible. She signed a lawsuit that will challenge the constitutional validity of Amendment 2. She wrote an article for an American national newspaper declaring she was proud to be gay and refused to live a lie. She has eagerly appeared before television cameras to voice her protest against Amendment 2. ''I've always had this outrage against being told how to live, what to say, how to act, what to do, when to do it,'' says Navratilova who grew up in a nation that by its communist ways did exactly that to Czechoslovaks. So now Navratilova has reason to believe there is life after tennis. But she will not become a politician. ''First of all, I can never be president,'' says Navratilova who always wants to be No 1 at whatever she does. She may be a US citizen now, but by not being US-born she has no right to stand for the presidency. ''But I can't see myself as a politician anyway. I just couldn't deal with all the back-slapping and glad-handing and worrying about being elected again,'' Navratilova said. ''I'm more a behind-the-scenes type, speaking out and making people aware of what is going on.'' Case in point is her campaign against Amendment 2. And any cause that draws Navratilova as an activist can be sure it could not have found a more articulate and educated advocate. She is a political junkie. She must read her newspapers and news magazines. She must watch her current affairs programmes. She is probably the only tennis player to have walked away from a tournament, in Washington DC, to listen to a speech in the US Congress. She can rattle off statistics like her crisp volleys, comparing the US with other countries on any social issue that is the topic of the moment whether it be abortion or homosexuals in the military. But it all comes at a cost. Most athletes are careful how they align themselves politically. Many prefer to avoid social issues and political agendas fearing their views pose a threat to their main source of income out of the sporting arena - endorsements. ''I just do what feels right from the gut,'' says Navratilova who last year backed the campaign to put Bill Clinton in the White House as she found comfort in his support of gay rights and horror in President Bush's intolerance of a woman's right to an abortion. ''If it means I won't get endorsements, that's tough. If it means I have a smaller house and a million dollars less, then that the price I have to pay.'' But then Navratilova has paid bigger prices for her sacrifices. In 1975, when still a teenager, she defected at the US Open in what an American nation, eager to embarrass any regime behind the Iron Curtain, trumpeted as a political statement. Yet it was not. Navratilova was then making a decision to further her tennis career. It was not that she did not have the political consciousness that is so evident today. Her life had been caught in a Soviet-inspired communist regime. Her mother and stepfather had been punished for rejecting the Communist Party in Czechoslovakia. ''They had menial jobs and were not allowed to use their intellectual powers,'' Navratilova says. ''They didn't have to be janitors, but they were in an office and never got promoted because of their past and their refusal to join the party. I was aware of that growing up.'' Navratilova could not afford to be so radical. Her rejection of the communists would have destroyed her tennis career. Her acceptance of the system would have made her a hypocrite. ''They wanted me in the communist youth party and to go to all these meetings with thousands of delegates,'' said Navratilova. ''I went for half a day. If I didn't go, I wouldn't have been allowed out [of Czechoslovakia]. I only did the absolute minimumrequired. You do what you have to to survive without hurting someone, hopefully.'' Her true political awakening - so evident now - came in 1980 when she sought her US citizenship. Fearful her homosexuality would deny her American citizenship, she did not apply for her passport in Virginia or Texas, where she had homes, but in the moreprogressive California. In America, Navratilova was finding she could have been the same ''non person'' she was in Czechoslovakia. And a decade later she has the same fear in Colorado where Amendment 2 will also classify her as a ''non person'' because of her sexual preferences. Not only in Colorado does Navratilova sense the double standards. ''I'm often invited to speak at schools,'' she says, ''but most of them wouldn't hire me to teach there.'' She does remain a popular choice for charity groups but is very selective in to what she will sign her name. ''I just don't want to be a name on stationery,'' says Navratilova. ''If I'm going to put my name on something, I want to be personally involved. ''I'll always be involved with one cause or another. I do believe that if you plug hard enough, things will happen. You can't be jaded. I just wish more people would do their little bit here or there because then we could really make a difference. Everylittle bit helps.'' Navratilova can now put down her racquet. She's found a soap box to replace it.