YOWERI MUSEVENI, the Ugandan President, cut short a visit to London last night to face the most serious political rival of his 18 years in power — a former comrade who has returned to Kampala four years after fleeing the country in fear of his life.

Mr Museveni, a hero of the bush war that ended the disastrous dictatorships of Idi Amin and Milton Obote, denied that he was flying home early for political reasons, but cancelled most of his engagements yesterday, including an official dinner.

For most of the past decade Mr Museveni has been hailed as a role model for modern African governance. He has been lauded by President Clinton, welcomed at the White House by President Bush and given lavish aid by international donors impressed by Uganda’s economic turnaround and relative success against Aids.

But the 61-year-old leader is now under growing international pressure to protect his legacy by stepping down after two terms in elected office.

But, in an interview with The Times hours before his departure, he gave the clearest signal yet that he intends to stand for a third five-year term next spring. He also refused to rule out the possibility that Kizza Besigye, the returning opposition leader, might be prosecuted for alleged sedition.

Mr Museveni shrugged off Colonel Besigye’s return as “not a problem”; called for the wholesale scrapping of trade subsidies that continue to cripple African economies; and offered an unusual method for measuring the incidence of homosexuality in Uganda.

It will do little to persuade the world that his undoubted achievements qualify him for the indefinite presidency he appears to be seeking.

If anyone can stop him, it may be Colonel Besigye, once Mr Museveni’s personal doctor, now leader of the opposition Forum for Democratic Change. He returned to Entebbe airport yesterday after four years of self-imposed exile in South Africa to denounce the intimidation that he claims marred Uganda’s last presidential election, in which he came a distant second, and to demand political reform.

Wellwishers crowded into his press conference and cheered him on his way, though many supporters claimed police had held them back from the airport. Mr Museveni, 3,000 miles away in London, appeared nonchalant. He denied a suggestion that his rival’s return posed a test of his tolerance, saying: “That gentleman exiled himself and has unexiled himself. That’s his business. Other presidential candidates in 2001 have all been enjoying life in Uganda.”

Will Colonel Besigye be able to do likewise? The question returned to Uganda’s headlines last week. Mr Museveni responded to rumours of Colonel Besigye’s return with a leaked letter to a Cabinet minister suggesting that his rival might face prosecution for alleged involvement with an opposition militia group. The letter was widely seen as a threat.

Yesterday the President distanced himself from the affair, insisting that Uganda’s director of public prosecutions would decide whether to press charges. “These are the ones who deal with that area of crime, if somebody has committed a crime,” he said. “And obviously no one is above the law.”

Colonel Besigye is almost certain to run in what promises to be a bitterly contested election in April. Mr Museveni, who vowed after his last win that he would not run again, has since prompted an amendment to the constitution to allow him a third term. The move has cost him much of the acclaim he earned as the architect of Uganda’s transformation from economic basket case to a darling of donor agencies, with healthy growth rates and success against the Aids epidemic.

He claimed that changing the constitution had nothing to do with ambition. “I’m not a careerist, I’m a freedom fighter,” he declared, claiming constitutional “rigidity” made no sense when Uganda’s challenges — such as Aids, fighting economic dependency and political fragmentation — remained daunting and long term. It was unclear which of Uganda ’s needs Mr Museveni feels only he can satisfy. He claimed the Lord’s Resistance Army, the rebel group accused of mutilations and of abducting up to 20,000 children in the north of Uganda, has been defeated, with indictments from the International Criminal Court likely to help in the pursuit of its remaining leaders in neighbouring Sudan.

Explore World News

• World Agenda

• Iraq News

• US & Americas News

• Europe News

• Middle East News

• Afghanistan News

• Asia News

• Africa News

• Ireland News

Times Recommends

• A doctor, a daughter and a man called Johnny
• Mona Lisa's smile may belie ill health
• ‘Parasite economy’ lies behind Greek tragedy