Madonna has stepped up her fight for gay rights in Russia by writing an open letter calling for change.

The Material Girl star sparked controversy during her trip to Russia last year (12) by publicly backing jailed punk stars Pussy Riot and voicing her support for the lesbian, gay, bisexual, and transgender (Lgbt) community. The move prompted activists in the country to file a lawsuit against the star, which was later dismissed, over claims she violated a local law banning the promotion of homosexuality.

Madonna has refused to back down, and she has now written an open letter demanding supporters around the world band together to "fight against the Russian government's campaign of hate".

The singer has thrown her support behind the Human Rights Campaign's Love Conquers Hate drive, which she insists is more relevant than ever for Russia as the 2013 Winter Olympics in Sochi approach.

She writes, "Right now in Russia, Lgbt people... are being targeted by hateful new laws that outlaw support for Lgbt equality. Even with the 2014 Sochi Olympics just a few months away, fair-minded Russians are facing fines, harassment, and violence at the hands of thugs.

"At this dangerous moment in Russian history, we as advocates have a responsibility to speak up and take our hopeful message global. That's why I'm joining Hrc's Love Conquers Hate campaign, in hopes that more and more fair-minded people around the world will stand up and fight against the Russian government's campaign of hate...

"The goal of these hateful laws (in Russia) is to leave Lgbt Russians feeling isolated. Worthless. Completely alone. Together, we can send a message to Lgbt Russians that the world is on their side, and that those who seek to support them aren't alone in this fundamental fight for fairness. It's time for love to conquer hate everywhere, for everyone. I hope you'll stand with me in this fight."