By Muvija M and William James LONDON (Reuters) -Britain accused Russian news channel RT on Wednesday of being a tool of a Kremlin disinformation campaign and asked the UK media regulator to take action if needed after Russia recognised two rebel regions of eastern Ukraine. Russian officials say RT is a way for Moscow to compete with the dominance of global media companies based in the United States and Britain that Moscow says offer a partial view of the world. Critics say RT, which broadcasts news in English, Arabic, Spanish and German, is the propaganda arm of the Russian state and aims to u…