"Why now? Is it to favour President Museveni or other people?" NRM MP Monicah Amoding wanted to know on Wednesday.
Her comments came hours before members of her own party prepared to present a bill in parliament to amend article 102 of the constitution, paving the way for Museveni to run in the next election in 2021.
"The constitution of Uganda requires that when a president clocks 75 years he can no longer contest for presidency and that is what we swore to defend and stand by," Amoding told RFI.
Museveni has support among many Ugandans for having restored peace and security after two brutal dictatorships, so many MPs from his party support the move for him to run again.
Epiphany in church
At 73, he is already one of Africa’s longest-serving rulers and his age has long been the subject of controversy.
This summer it apparently emerged that the ageing leader was in fact born in 1947 and not 1944, which would make him three years younger than he really is and, more importantly, eligible to run in 2021.
The moment of epiphany occurred during an excursion to the church where he was baptized. A photo of him pouring over the archives went viral on social media and spawned debate on how old he really is.
"He's a very dishonest man," Wilfred Niwagaba, a former NRM MP who has turned independent, told RFI. "Of course he would have wished to be younger than his age. But, the fact is, he's even older than the age he portrays. But I know he is definitely behind this move to have this age limit removed from our constitution."
While the church may have helped Museveni discover his real age, for MP Muhammad Nsereko of Kampala Central, the institution has been less forthcoming on the constitutional reform debate.
"Religious leaders, where are you?" he asked at a press conference outside parliament on Wednesday. "On the marriage and divorce you are very vocal, but where are you when Ugandans are talking about the age limit?"
Nsereko was among several NRM MPs to speak up against the motion, which is likely to take at least a year to make it through parliament.
Bill likely to pass
Numbers-wise, however, these dissenting MPs are likely to have trouble gathering enough support to overturn NRM's 293 majority in parliament.
"We're calling everyone and asking them to vote this down," says Niwagaba. "The public must be sensitised. Uganda as a country has never had any peaceful transfer of power from one president to another. And the presidents we’ve had have all tended to be life presidents."
Amoding doesn't want that for Museveni.
"Our president needs to nurture young people," she argues. "This is the time for him to nurture a successor, a capable young man or woman who can steer this country forward."
The current chairperson of the Uganda Women Parliamentary Association made headlines on Tuesday when she became one of only two NRM MPs to oppose a resolution to pass the motion.
"We want Museveni to end with a good legacy, we want him to transit, to help this country transit in a smooth and good manner. Don't let five years spoil it."
Museveni himself hasn't commented on whether he wants to seek another term.
In a 2012 TV interview, he dismissed the idea of ruling beyond the age of 75, saying it had been scientifically proven that one would have less “vigour” past that age. But with people “begging him” to continue ruling, he might as well extend his term of office to 40 years and counting.
He already benefitted from changes to the constitution back in 2005, which scrapped the cap on two five-year terms. But polls today show that two thirds of Ugandans want him to retire.
On Friday, the president turns 74. On social media, users are already speculating which birthday he'll be celebrating this year.