LUSAKA (Reuters) - Zambian opposition leader Hakainde Hichilema, a longtime rival of President Edgar Lungu, denied plotting to overthrow the government when he appeared in a Lusaka court on Monday in a case that has heightened political friction in the country.

FILE PHOTO: United Party for National Development (UPND) Presidential candidate Hakainde Hichilema looks on during a rally in Lusaka, January 18, 2015. REUTERS/Rogan Ward/File Photo

Government and legal sources told Reuters on Sunday the government planned to drop the treason charges against Hichilema and release him from prison under a deal brokered by the Commonwealth secretary-general.

But a government source said later that the application to discontinue the case would now be made on Wednesday.

Hichilema -- commonly known as HH -- and five others were arrested in April and charged with treason after Hichilema’s convoy failed to make way for Lungu’s motorcade.

He was initially charged with treason for obstructing the motorcade then was later accused of plotting to overthrow the government between Oct. 1 last year and April 8 this year.

An amended indictment said he plotted to unseat the government between April 5 and 8 by mobilizing his supporters for a ceremony to give him the status of Zambian president.

“HH and the other five co-accused have taken plea and denied the charge of treason,” UPND spokesman Charles Kakoma told reporters on Monday.

The case has raised political in tension in Zambia, Africa’s second-largest copper producer and traditionally a stable democracy. Amnesty International has said the treason charges are trumped up and called for his release, as have local church leaders.

Hichilema and Lungu have long been rivals. His United Party for National Development (UPND) lost an election to Lungu’s Patriotic Front (PF) in August last year but his legal challenges claiming the poll was rigged failed.

In June, parliament suspended 48 opposition lawmakers for boycotting a speech by Lungu.

In July, Lungu imposed a state of emergency to deal with what he called acts of sabotage by the opposition, including

arson attacks on market places and court-houses. Critics say

the emergency powers will be used to harass political opponents.

BACK TO JAIL

Police in riot gear stood outside the High Court precinct on Monday and reporters for foreign news agencies were not allowed to cover the court proceedings.

Defense lawyer Jack Mwiimbu told Reuters that the adjournment was procedural.

“Our defense team has just prepared for trial but if there will be any such gestures, they will be welcome,” Mwiimbu said when asked whether the prosecution had indicated their plans to discontinue the case.

Hichilema, an economist and businessman, has been held in prison since his arrest. The six were detained in custody after taking their plea.