A Bangladesh court is expected to rule Thursday on a challenge to the legality of the nation's biggest Islamic party, which could bar the party from contesting future polls, lawyers said.

The High Court will announce its decision on the legality of Jamaat-e-Islami after a petition argued that the party's charter conflicted with the constitution.

A decision scrapping Jamaat's political registration could trigger fresh protests in the politically volatile country, already reeling from the deadliest violence in its history over war crime verdicts passed on Jamaat's top leadership.

The lawyer for the petitioner, Sheikh Rafiqul Islam, told AFP that Jamaat's charter violates the country's secular constitution adopted in 2010 as it calls for the rule of Allah and discriminates against minorities and women.

"If the court cancels Jamaat's registration, it cannot take part in any polls under the country's current election rules," Islam said.

Defence lawyer Tazul Islam said no clause of the party charter was in conflict with the constitution.

"If they scrap Jamaat's registration, 28 more parties will also face the same fate automatically," he said.

Secular protesters have long demanded that Jamaat be banned for its role in the 1971 war in which it opposed Bangladesh's breakaway from Pakistan.

Top Jamaat leaders are being tried for crimes during the war and four of them have been sentenced to death for murder, mass murder, rape and religious persecution during the struggle.

Protests over the verdicts have sparked violence in the country in which at least 150 people have been killed during street clashes.

Jamaat says the trials are a sham aimed at eliminating the party, which is also a key opposition force.