The vice president of Zimbabwe's opposition party, who also heads the opposition in parliament, was expected, during a court appearance Tuesday, to be charged with trying to overthrow the government. The charges against the senior party official, Gibson Sibanda, are some of the most serious in Zimbabwean law.

Police say Mr. Sibanda will be charged under Section Five of the Public Order and Security Act. According to the police, he will be charged with defying the constitution by trying to overthrow the government.

The charges relate to the successful general strike called two weeks ago by the opposition Movement for Democratic Change.

In particular, police say, they have linked Mr. Sibanda to various acts of violence during the strike, such as the torching of three buses.

If Mr. Sibanda is found guilty the court has no option but to send him to jail, as there are no provisions for a fine.

However, the 59-year-old Mr. Sibanda is no stranger to political upheavals. He spent three years in detention during the Rhodesian era as a member of the first black nationalist organization, The Zimbabwe African Peoples Union.

He was only released when the country gained independence from Britain in 1980. Mr. Sibanda then returned to his job on the national railways and revitalized large sections of the trade union movement. He went on to become elected president of the Zimbabwe Congress of Trade Unions in 1989.

He was one of the main organizers behind the formation of the Movement for Democratic Change, which emerged out of the trade unions, and was elected its deputy president in February 2000.

Mr. Sibanda's arrest and subsequent charges have sent shock waves through Zimbabwe's civil rights organizations.