Co-leader of the Scottish Green Party and MSP for the Glasgow area since 2003.

Over the past 15 years he has become one of Scotland’s most notable voices on the subject of climate change and the environment, winning over many converts to the Scottish Greens with his passionate views about the fate of the planet.

His other specialist areas include civil liberties, energy, food, IT, fair work and equalities.

After attending Manchester Metropolitan University, he worked in the areas of gay men’s sexual health, principally in HIV prevention and equality campaigning, before entering politics.