A Bangladesh court on Tuesday doubled a jail term for imprisoned opposition leader Khaleda Zia from five to 10 years following a prosecution appeal.
The decision came the day after Zia, 73, was ordered jailed for seven years in a separate case, piling pressure on the opposition ahead of a national election.
The increased term was ordered over embezzlement charges for which Zia, arch-rival of Prime Minister Sheikh Hasina, was sentenced in February.
"The high court has upheld the lower court verdict and raised the jail sentence from original five years to 10 years," anti-corruption commission prosecutor Khurshid A Khan told AFP.
The Bangladesh Nationalist Party (BNP), the main opposition movement that Zia still leads from behind bars, has vowed nationwide marches later Tuesday to protest the verdict.
The latest court ruling deals a crushing blow to the BNP and its embattled leader, who despite being jailed had clung to a faint hope of running against Hasina in election slated for December.
"She cannot contest the elections unless the conviction is set aside by a higher court," Bangladesh's attorney general Mahbubey Alam told AFP.
Zia was originally found guilty and sentenced to five years for embezzling money meant for an orphanage, a charge her supporters say is politically motivated.
That verdict in February triggered violent clashes in major cities across the Muslim-majority democracy of 160 million, with opposition demonstrators clashing with police and activists from the ruling party.
Zia, widow of assassinated military dictator Ziaur Rahman, faces dozens of separate charges related to violence and corruption that her lawyers insist are baseless.
Her son and heir-apparent Tarique Rahman was jailed for life in absentia this month over a 2004 grenade attack on a Hasina political rally. Rahman lives in exile in London.
In recent months, her health has deteriorated inside the abandoned 19th-century jail -- where she is the only inmate -- with a physician saying that arthritis has rendered Zia's left hand useless.
Her lawyers have accused the government of putting her health at risk by refusing her specialised care in prison.