The largest Islamist party in Bangladesh has been banned from taking part in the forthcoming general election on the grounds that it is against secularism.
The ruling by the high court in Dhaka will raise tensions in the volatile country, where rival protests and strikes have intensified in recent months.
Jamaat Islami (JI) is a key member of an alliance of opposition parties that will seek to oust the ruling Awami League at the polls later this year. Although popular support for the party is limited, its supporters can swing the result in scores of constituencies.
A report from Human Rights Watch accuses security forces of using excessive force in responding to the protests. At least 150 protesters have been killed and 2,000 injured since February this year.
While large numbers of protesters have been arrested, the Bangladeshi authorities have made no meaningful efforts to hold members of the security forces accountable, the report says.
Brad Adams, Asia director at Human Rights Watch, said street protests were likely to be more frequent in the coming months. "The risk of further violence is high ... unless the government takes firm action to rein in the security forces, there is going to be a lot more blood on the streets before the year is over," he said.
Many of the protests have been prompted by a series of judgments by a tribunal sentencing senior JI officials to death or life imprisonment for crimes they are alleged to have committed during Bangladesh's war of independence from Pakistan in 1971. JI opposed the split with Pakistan.
The high court ruling comes four years after a group of former politicians and moderate Muslim leaders filed a petition seeking to cancel JI's registration.
Syed Tayabul Bashar, of the Bangladesh Tariqat Federation, said: "We are very happy with the verdict today. Jamaat Islami has no democratic right in this country because its actions in the liberation war were against our country."