LUSAKA (Reuters) - Zambia's Supreme Court has rejected an application by the main opposition party to stop President Edgar Lungu's inauguration, set for Tuesday after last month's contested election, a lawyer for the opposition leader said on Monday.

The election row - which followed violence between rival campaign supporters in what is otherwise considered one of Africa's most stable democracies - could damage Zambia's ability to attract investment critical to reviving the economy.

"The court has declined to grant the application on grounds that as a single judge he has no jurisdiction," Keith Mweemba, a lawyer for opposition leader Hakainde Hichilema told journalists.

Lungu's inauguration after the Aug. 11 election was postponed because Hichilema challenged the result in court, saying the vote was rigged. A law introduced in January says the winner of a presidential vote cannot be sworn in if their victory is contested in court.

On Friday the Lusaka High Court threw out an attempt by Opposition United Party for National Development (UPND) leader Hichilema to overturn a Constitutional Court decision not to give him more time to legally challenge Lungu's re-election.

Mweemba said his clients planned to file another application before the full bench of the Supreme Court.

Zambia will press on with swearing in its president for another five-year-term on Tuesday after Lungu won 50.35 percent of the vote according to the official results.

Prospects for resuming critical budget support talks with the International Monetary Fund have been dimmed by delays in swearing in a new head of state.

Lungu has been the head of the ruling Patriotic Front since its leader, Michael Sata, died in 2014. He won the presidency the following year, defeating Hichilema in their first electoral confrontation.

In a separate ruling, the broadcasting regulator lifted the suspension of Muvi TV, the nation's largest private television station after the station admitted to producing "unfair and unbalanced content" during the election period.

In August the Independent Broadcasting Authority (IBA) suspended the licenses of three private broadcasters, saying they had conducted themselves in an "unprofessional manner" during and after the election. The IBA said the station's coverage "posed a risk to national peace and stability, but gave no details.

(Reporting by Chris Mfula; Writing by Nqobile Dludla; Editing by James Macharia)