How much less will the women earn than the men at this year's Wimbledon?
The prize money at Wimbledon this year is higher than at any other tournament in world tennis. The total pot is £10,378,710, an increase of 2.9 per cent on last year. The total prize fund for the women's singles is £4,446,490 (3.4 per cent up on last year), while the men will be competing for £5,197,440 (a 3.3 per cent increase).
If Roger Federer retains his men's title he will receive a cheque for £655,000, while the women's champion will be paid £30,000 less at £625,000. Even players who are knocked out in the first round are well rewarded, men receiving £9,380 and women £7,860.
Do other tournaments pay different rates?
Most tournaments are single-sex events. The women play on the Sony Ericsson Women's Tennis Association tour, while the men play on the Association of Tennis Professionals tour. The major events where men and women play at the same tournament are the four "Grand Slam" competitions, the Australian Open, French Open, Wimbledon and the US Open.
Over the year, men are paid considerably more than women. Where there are comparable single-sex tournaments, the men's prize money nearly always exceeds the women's fund.
As for the Grand Slam events, the US Open and the Australian Open started paying equal prize money several years ago. The French Open this year awarded the same prize money to its male and female champions (£646,000) for the first time, though the total prize pot for the men (£4.42m) was still bigger than the women's (£4.05m). Roger Federer, the beaten men's finalist, earned £328,000, while Svetlana Kuznetsova, his female equivalent, earned £323,000.
Women play shorter matches. Is this a factor?
Women are on court for a shorter length of time than men at the Grand Slam tournaments. Their matches are over the best of three sets whereas the men play the best of five.
Billie-Jean King, a long-time campaigner for equal pay, says: "When Wimbledon first started off, women did play best of five sets, but a woman - probably wearing a corset - fainted, and the all-male board decided that we could only play best of three sets. We have offered to play five-set matches any time they want."
However some current players, like Justine Henin-Hardenne, the French Open champion, would be opposed to any such move. "We have to accept that men and women are different," she said this week.
Making women's matches best-of-five-sets would make scheduling difficult, and would probably not please broadcasters, who wield considerable power. They do not like the fact that there is no guessing how long a tennis match will last, and if anything the trend is towards shorter matches in tennis.
In justifying Wimbledon's decision to pay women less, Ian Ritchie, the new chief executive, says it is a question of being "fair" to both sexes. He points out that, because they played shorter matches, women players were actually paid more per game than men at the 2005 Championships. The last eight players in the women's singles took home £1,432 for every game they played, while the men were paid £993 per game.
Would the public rather watch men or women?
Television viewing figures and attendances at tournaments show that, in general, fewer people watch women's matches than men's matches, although that trend might be changing. At Wimbledon last year, for example, the men's final between Roger Federer and Andy Roddick was watched by a BBC TV audience of 5.8m, while 6.8m watched the previous day's women's final between Venus Williams and Lindsay Davenport.
Corporate hospitality prices are also a good indication of what the public wants to see. At Wimbledon last year some firms were charging twice as much for hospitality on men's quarter-finals day as they were for the equivalent women's programme.
Aren't sponsors just as interested in women as men?
Comparing commercial endorsements for men and women is difficult because sponsors and advertisers are often looking for different things from the two sexes. With both sexes, moreover, the leading players attract the vast majority of the money.
The leading women - particularly if they are considered glamorous - are in huge demand by sponsors. Maria Sharapova earned more than £10m last year, most of it off the court. Maria Kirilenko, another 19-year-old Russian, is ranked only No 20 in the world but is set to make a fortune out of her looks.
Isn't women's tennis more competitive?
The top of the women's game is probably as strong today as it has ever been. Until Henin-Hardenne retained her French Open title earlier this month, the preceding eight Grand Slam tournaments had been won by eight different women. The problem for women's tennis is the lack of strength in depth outside the top dozen or so players. The fact that Martina Hingis, returning this year after three years out with injury, has rapidly climbed back to No 15 in the world is as much a reflection of the poor quality outside the top group as it is of her talent.
Can unequal pay be justified in the modern age?
Tessa Jowell, the Minister for Sport, said in a recent letter to Tim Phillips, the Wimbledon chairman, that the pay gap did not reflect "the society of equal opportunity" that Britain had become in the 21st century and that it was "tarnishing the image" of Wimbledon. Venus Williams echoed that argument when she said: "This is not just about women's tennis but about women all over the world."
Those who support equal pay for women feel this case is unanswerable. Whatever the rights and wrongs over lengths of matches and television figures, they argue that in this day and age, the best women should be paid the same as the best men.
Is Wimbledon's gender divide outdated and wrong?
* The sport is just as competitive for women as for men
* In today's world, giving women less prize money is demeaning and outdated
* Just as many viewers watch women's tennis as men's - in some cases more
* Men play longer matches, over the best of five sets instead of three
* Men's tennis arouses more interest than women's in terms both of sponsorship and overall attendance
* Per game played, men actually earn less than women