Uganda's Supreme Court on Tuesday began hearing a petition seeking to challenge a constitutional court decision removing an age limit cap of 75 for presidential candidates.
Critics of the decision argue it would allow President Yoweri Museveni, 74, to seek re-election for a sixth term in 2021.
A bill removing the limit was signed into law in December 2017 after a chaotic passage through parliament that saw MPS engaging in fisticuffs.
The constitutional court upheld the amendment in a ruling in July 2018.
Opposition lawmaker Winnie Kiiza and activist Kassim Male Mabirizi of the Uganda Law Society filed the petition challenging the constitutional court decision.
They want the court to decide whether the amendment violated the constitution as it "was rushed through parliament amidst violence and chaos, where members of the opposition were either arrested or beaten by police and army", Kiiza's lawyer Ladislaus Rwakafuzi said.
"The other element of our appeal is for court to decide whether the president, who was elected before the constitutional amendment lifting the age limit cap of 75 years, should remain in office after clocking 75 years," he added.
Having seized power at the head of a rebel army in 1986, Museveni is the only president most Ugandans have known in a country where the median age is less than 16.
In 2005 Museveni scrapped a two-term presidential limit which has allowed him to keep running for office.
Young Ugandans have recently been energised by pop star-turned-MP Bobi Wine, who spearheaded protests against the age-limit amendment and has rapidly become a thorn in the government's side.