A group of top Russian liberals is joining forces to keep Vladimir Putin from staying in the Kremlin after 2008.
Kasparov and allies are against "tsar-like" presidents
They concede that they cannot stop the popular president from being re-elected this March, but have vowed to scotch any efforts to extend his term.
The group is led by chess champion Gary Kasparov, a leading critic of Mr Putin.
"We concede that we are a minority, but a minority united in its belief that democratic values are under threat in Russia," they said in a statement.
Russian liberals suffered a crushing defeat in December's parliamentary elections.
United Russia, backed by Mr Putin, won more than 300 seats in the 450-seat Duma, while the two main liberal parties are barely represented.
"Those who represented democracy, the Union of Right Forces and Yabloko, have been consigned to the dustbins of history," Mr Kasparov told the Russian daily Nezavisimaya Gazeta.
"We have to start all over again."
His group, called "2008: Free Choice", also includes liberal politician Boris Nemtsov, Soviet-era dissident Vladimir Bukovsky and TV political satirist Viktor Shenderovich, whose programme was recently taken off the air.
They issued a statement on Monday accusing President Putin of trying to consolidate his "tsar-like" power at all costs.
They criticised his control over the parliament and the media, and what they called the "flat-out falsification of the last election's results".
"We will make sure a new president is elected in 2008," it said.
Some of the country's most prominent politicians have decided not to run in the presidential polls on 14 March, including ultra-nationalist Vladimir Zhirinovsky.
Mr Zhirinovsky had taken part in every Russian presidential election since 1991.
Among the hopefuls are former boxer Oleg Malyshkin, supported by the Communist Party, as well as a former Chairman of the Central Bank, Viktor Gerashchenko, and the liberal politician, Irina Khakamada.