Jailed Russian oil tycoon Mikhail Khodorkovsky has had his appeal against convictions for fraud and tax evasion dismissed by a court in Moscow.
Mr Khodorkovsky has vowed to fight on against his conviction
Judges took less than a day to reach their decision, following a series of adjournments and delays in the case.
The court upheld all but one count against Khodorkovsky, cutting his jail sentence from nine to eight years.
Lawyers for the ex-boss of Yukos said the speed of the court's ruling proved the case was politically motivated.
"The fact that this court has delivered its ruling in just one day has proven eloquently everything we have been saying about the political control of this process," said Robert Amsterdam, a member of Khodorkovsky's legal team.
1963 - Born in Moscow; parents were chemical engineers
1980s - Sets up computer and software business with fellow students at Mendeleeva Chemical Technical Institute
1987 - Founds Menatep bank
1994 - Buys fertiliser company Apatit at auction
1995 - Buys oil company Yukos for $300m, with Menatep assuming $2bn in debt
October 2003 - Arrested on charges of embezzlement, tax evasion and fraud
June 2004 - Court case begins
May 2005 - Found guilty of six of seven charges and sentenced to nine years in jail
The court's ruling, and the reduced sentence, applies to Khodorkovsky's business associate Platon Lebedev, who was also convicted in May.
Speaking before the court's judgement, Khodorkovsky condemned the "Kremlin bureaucrats" he said had orchestrated the case against him and the oil firm he once headed.
"There is no justice in this case," he said.
But state prosecutor Dmitry Shokhin welcomed the court's decision to reject the appeal.
"Now we can say with complete certainty that Khodorkovsky and Lebedev committed serious crimes, for which they have been punished with prison terms," he said.
Khodorkovsky's 11-month trial ended in May with his conviction on six of the seven charges of tax evasion, fraud and embezzlement he had faced.
He and Lebedev were ordered to pay 17bn roubles (£330m; $600m) in taxes and penalties.
Correspondents say the jailed tycoon has become a focus for opponents of President Vladimir Putin, who believe Khodorkovsky is the subject of a political vendetta for having funded opposition parties.
Khodorkovsky had planned to contest a parliamentary by-election for the State Duma lower house in early December.
Russian law permitted Khodorkovsky to stand for parliament while his appeal was pending.
However, the court's decision to dismiss the appeal will disqualify him from running for public office.
Supporters of Khodorkovsky said the Kremlin had rushed through his appeal to stop him from contesting the Moscow by-election - a move which would have been embarrassing for President Putin.