Some 52 Olympians including Sochi competitors and former medalists have signed onto a statement to call on Russia to reconsider recently introduced anti-gay laws that forbid "gay propaganda" aimed at minors. Gay pride marches and protests in support of gay rights have routinely been banned in all Russian cities in the past, and activists attempting to hold rallies are often detained by police.

The online petition, which was launched in June last year and appears on the websites of global equality group All Out and Athlete Ally, has since gathered more than 405,000 signatures.

It states: "We stand with citizens across Russia who are calling on their government to stop the crackdown against lesbian, gay, bi and trans people that is fueling anti-gay violence. We urge leaders around the world and within Russia to work to eliminate all anti-gay laws and protect all citizens from violence and discrimination in Russia."

The two groups also announced protests to be held in Moscow, Sochi, London, Rio de Janeiro and other cities on February 5, two days before the start of one of the most controversial Olympic Games in years.

The "Pro Allies" signatories to the "Principle Six" campaign – named after the clause in the Olympic charter that declares any form of discrimination on the grounds of “race, religion, politics, gender or otherwise” to be “incompatible with belonging to the Olympic movement” – include openly gay former Olympians Greg Louganis who has won four gold medals and one silver for diving, and tennis legend Martina Navratilova.

Among the Sochi-bound competitors who signed the statement are Australian snowboarder Belle Brockhoff who came out publicly as lesbian last year, and New Zealand speed skater Blake Skjellerup who is gay.

Other allies include Canadian alpine skier Mike Janyk, Australian bobsleigh pilot Heath Spence who are both headed to Sochi, former World No. 1 tennis player Andy Roddick and Shaun T, a celebrity fitness trainer best known for his Insanity home fitness program.

While the IOC has confirmed that Principle 6 of the Olympic Charter does apply to discrimination on the grounds of sexual orientation, campaigners say they have not spoken out sufficiently against Russia’s anti-gay laws that prohibit the word “gay” to be said in public.

IOC President Thomas Bach last week said that athletes are free to speak out on any political issues at news conferences at the games. Sochi 2014 chief executive Dmitry Chernyshenko on the following day “clarified” his comments saying that athletes who wished to speak out against the anti-gay legislation would have to do so in a special "protest zone" located some 11 miles (18km) from the Olympic Village.