Russian President Vladimir Putin has dismissed his government in a live television broadcast.
Viktor Khristenko becomes Putin's temporary prime minister
The surprise move comes weeks before a presidential election which Mr Putin is expected to win by a landslide.
Deputy Prime Minister Viktor Khristenko has been named as temporary replacement for Prime Minister Mikhail Kasyanov.
Mr Kasyanov was known to be unpopular with Mr Putin, but his future had been expected to be secure until after the 14 March election.
He was among the Kremlin's few survivors from the camp of Mr Putin's predecessor, Boris Yeltsin. Most liberal Yeltsin-era figures had already been driven out by Mr Putin's new breed of appointees.
He also had links with the oligarchs - the super-rich businessmen who made their fortunes during Mr Yeltsin's post-communist privatisation era but have fallen out of favour since Mr Putin's election.
The announcement on state-run television was trailed simply as a statement.
Mr Putin said the decision did not reflect on the government's performance, which was satisfactory "on the whole".
"This is linked to my
wish to set out my position on what the country's course will be
after 14 March 2004," he said.
Mr Putin said he had the power to ask for the government's resignation under article 117 of the Russian constitution.
Russian share prices dipped after his announcement.
Analysts said Mr Putin's main target had almost certainly been Mr Kasyanov, but under the constitution he was unable to remove him without firing the entire cabinet.
"Putin just simply can't stand Kasyanov," said Igor Bunin of Russia's Centre for Political Technologies.
"There has been a lot of disagreement over economic policy, like issues related to taxes, mortgage schemes and so on."
A 46-year-old former economics professor
Rapidly rose to deputy PM under Boris Yeltsin
Served as emissary to the IMF
Seen as a technocrat, loyal to Putin
Voters are likely to respond positively to the signal that Mr Putin is cutting Russia's last tie with the Yeltsin years, he added.
"If his rating stands at 80% now, it will jump to 85% after this announcement," he said.
Most analysts, however, had expected Mr Putin to act against Mr Kasyanov only after the election.