- Mr Gandhi has been sentenced to two years in jail for 2019 comments about Prime Minister Narendra Modi's surname at an election rally.
- Mr Gandhi's lawyer, Kirit Panwala, told the BBC that they will challenge the decision in the Gujarat high court.
An Indian court has rejected opposition leader Rahul Gandhi's appeal seeking a stay on his conviction in a criminal defamation case.
The decision extends the uncertainty over whether he can contest in national elections due next year.
Mr Gandhi has been sentenced to two years in jail for 2019 comments about Prime Minister Narendra Modi's surname at an election rally.
He won't be arrested until he has exhausted all legal appeals.
Mr Gandhi's lawyer, Kirit Panwala, told the BBC that they will challenge the decision in the Gujarat high court.
Mr Gandhi lost his seat in parliament a day after his conviction on 23 March due to a Supreme Court order which says that a lawmaker convicted in a crime and sentenced to two or more years in jail is disqualified with immediate effect.
The Congress has criticised Mr Gandhi's conviction and accused the governing Bharatiya Janata Party (BJP) of political vendetta.
The BJP has denied this, saying that due judicial process was followed in the case.
Earlier this month, Mr Gandhi had filed appeals to suspend his sentence, or secure bail, and to suspend his conviction in a court in Surat.
The court had granted Mr Gandhi bail to appeal against his conviction, but it's the stay or suspension of his conviction that's crucial to reinstating him as an MP.
The defamation case against Mr Gandhi, brought by BJP lawmaker Purnesh Modi, revolved around comments Mr Gandhi made in Karnataka state in 2019 during an election rally: "Why do all these thieves have Modi as their surname? Nirav Modi, Lalit Modi, Narendra Modi," he said.
Nirav Modi is a fugitive Indian diamond tycoon while Lalit Modi is a former chief of the Indian Premier League who has been banned for life by the country's cricket board.
Purnesh Modi in his complaint alleged that the comments had defamed the entire Modi community. However, Mr Gandhi said that he made the comment to highlight corruption and it was not directed against any community.