A leading Zimbabwean opposition lawmaker pleaded not guilty to charges that he planned to overthrow President Emmerson Mnangagwa, a lawyers’ group said on Monday, the latest in a series of cases to target government critics.

Job Sikhala, vice chairman of the main opposition the Movement for Democratic Change (MDC) party, was arrested in July, after he criticised the government at a rally in the southern Masvingo province.

The 47-year-old was subsequently released on bail.

At the opening of the trial on Monday Prosecutor Tawanda Zvekare told the court in Masvingo city that Sikhala was planning to subvert the government “through unconstitutional means” at the MDC event.

Zimbabwe Lawyers for Human Rights said Sikhala pleaded not guilty and was seeking to have the subversion charges dropped.

“(Sikhala’s prosecution) is just harassment of the opposition legislator through the use of the criminal justice system,” said rights lawyers grouping.

Several government critics have been charged with subversion since Mnangagwa came to power in 2017 following a coup that ousted long-time ruler Robert Mugabe.

Prosecutors last year dropped treason charges against leading civil rights activist and priest Evan Mawarire, who was arrested in January 2019 for calling on Zimbabweans to miss work for a day in protest at the doubling of fuel prices.