The Olympics is for athletes of all nations, without bar on gender, creed or race – the only demand is that they excel at their sport. Some of the modern Games' greatest moments have been when the forces of bigotry have been made to face the simple truth that no race is better or worse than another – as when Adolf Hitler, hosting the games in 1936, watched Jewish and black athletes beat Germans.

So why on earth is Saudi Arabia taking part in London in 2012?

As a new report from Human Rights Watch today points out, the country violates the basic equality rules of the Olympics Charter. No Saudi woman has ever represented her country in the Olympics, and the country's restrictions on women taking part in sport, recreational or competitive, amount to intolerable, blanket discrimination. Girls do not even receive physical education in schools:

Saudi government restrictions put athletics beyond the reach of almost all women. There is no government sports infrastructure for women, with all designated buildings, sport clubs, courses, expert trainers, and referees limited exclusively to men. The ban on women’s private, for-fee sports clubs has forced women to restrict themselves to fitness gyms that rarely feature swimming pools, a running track, or playing fields for team sports. Membership fees there are beyond the means of many ordinary Saudi women and girls. Official sporting bodies hold no competitive sports for Saudi women athletes in the kingdom and do not support Saudi sportswomen in regional or international competitions.

Only two other countries have never sent a woman to the Olympics: Qatar and Brunei. But they do not bar women, and their female athletes have competed in other sporting competitions. (Qatar has said it does intend to send female competitors to London in July.)

Kick them out

There's precedent for a ban by the International Olympics Committee: the Taliban-run Afghanistan was banned from the Sydney Olympics in 2000, partly because of the regime's attitude to women. But Saudi Arabia appears to be a special case. Although it clearly violates the IOC's rules, the committee has never issued more than a feeble slap over the wrist to the oil-rich kingdom.

Saudi Arabia is, of course, far wealthier than Afghanistan – and the IOC has long shown how susceptible it is to the power of hard cash.

Take action: Let's force Britain, the host nation, to act. Sign this petition demanding that British prime minster David Cameron bars Saudi Arabia from this summer's Olympics in London, unless the country plays by the rules.

Sign up also with No Women. No Play, a website protesting at the inclusion in the Olympics of countries that discriminate against women in sport.