David Cameron wants his visit to China to focus on improving links and promoting trade but some campaigners say the human rights situation in China's Tibetan areas is getting worse and more than 120 Tibetans have set fire to themselves in the past 2 years in protest at the nature of Chinese rule.

They insist Mr Cameron should raise the issue with Chinese leaders.

Most journalists have been prevented from reporting from Tibetan areas in recent years but our China correspondent Damian Grammaticas has gained rare access for this report.