Bobi Wine, denied access to the government-run television network, gave a press conference on Saturday, September 22, and uploaded it to YouTube.
Last month the 36-year-old singer, who was born Robert Kyagulanyi Ssentamu, was beaten and tortured by police earlier and flew to the United States for treatment of his injuries. His driver was shot dead.
"It looks like the government is determined to keep us slaves in our own country but I have come to continue exactly where I stopped. I am going to fight on…I cannot be a refugee," he said.
Bobi Wine was only four years old when Museveni came to power and he is counting on support from Uganda's youth, which represent a large proportion of the country's population.
Uganda has one of the youngest and most rapidly growing populations in the world.
Museveni came to power in 1986 when his rebel army, the National Resistance Movement, ousted a corrupt government a year after his arch-enemy Milton Obote had been toppled in a military coup.
But Nic Cheeseman, Professor of Democracy at the University of Birmingham and founder of Democracy In Africa, said power had changed him.
"His early image as a reformer and new breed of leader has now well and truly been destroyed," Prof. Cheeseman told Sputnik.
"Museveni remains in power for a number of reasons — he believes he needs to do so in order to secure his legacy, he and his allies have too many vested interests in remaining in power, there is no obvious replacement, and the NRM regime is strong enough to divide and rule the opposition," Prof. Cheeseman told Sputnik.
"His determination to be a ‘president for life' does mean that the chances of him ending up as a Robert Mugabe figure are increasing all the time," Prof. Cheeseman told Sputnik.
Museveni was the darling of the West for years as he brought back peace, stability and free market economics to a company that under Obote and his predecessor Idi Amin had known only violence, civil war and flirtations with socialism.
For many years — right up until 2005 — northern Uganda was terrorized by the crazed fanatics of Joseph Kony's Lord's Resistance Army and was also preoccupied with the conflicts in neighbouring Rwanda and the Democratic Republic of Congo.
But in recent years there has been a growing feeling that Museveni, who turned 74 last week, has overstayed his welcome.
In 2016 he was re-elected president but the defeated candidate, Kezza Besigye, cried foul and claimed the poll was rigged.
Last year Bobi Wine, a rapper and singer, produced the hugely popular song Freedom, which contained several abrasive lyrics aimed at Museveni.
"I don't feel safe at all…My family lives in fear," the singer said on Monday, September 24.
He faces trial for treason over an incident last month in which the president's convoy was stoned in the northern town of Arua.
Behind the scenes US and European diplomats are thought to be urging Museveni to prepare a timetable for leaving or end up going the same way as Zimbabwe's President Robert Mugabe, who was ousted by the country's army last year.
Like Mugabe, Museveni's powerbase is in the countryside and his opponents draw much of their support from younger, urban voters.