Mikhail Kasyanov, former Russian prime minister and a possible presidential candidate to succeed Vladimir Putin in 2008, appealed yesterday to leaders of the Group of Eight leading industrial nations to spell out their concerns "firmly and publicly" about the drift away from democracy in Russia.

Speaking at the International Institute for Strategic Studies in London, Mr Kasyanov criticised a series of constitutional changes implemented by Mr Putin that had undermined party politics in Russia and weakened its federal system.