Amama Mbabazi, an ex-prime minister and former close ally of 70-year-old President Yoweri Museveni, has announced he will be challenging him for leadership of the ruling party and the presidency in the 2016 poll.
Amama Mbabazi, who was once Uganda's prime minister and secretary-general of the ruling National Resistance Movement (NRM), declared his ambition to become president in a YouTube video.
He told Ugandans the 2016 elections were about "breathing new life into our system of government that has become weak and inefficient."
"We need to revive our mission to improve education, health and public services," he said.
Mbabazi said he would be seeking the NRM nomination in a direct challenge to Museveni, who has already been given the green light to be their candidate in the 2016 poll.
Security forces surrounded Mbabazi's home after he announced his candidacy, the news agency AFP reported, quoting his wife, Jacqueline.
Mbabazi said he would be challenging Museveni for the chair of the NRM and then the presidential nomination.
Mbabazi, who is also a former defense minister, was sacked as prime minister by Museveni last year. The ruling party then ousted him from the post of secretary-general.
So would Mbabazi be able to mount a credible challenge to Museveni? Godber Tumushabe, an expert on governance and development at the Great Lakes Institute for Strategic Studies said that Mbabazi still has a power base within the NRM.
"I think he has been building up an infrastructure [within the NRM] that could be a game changer in the way we do the campaigns in the coming months," he told DW.
Tumushabe also said Mbabazi "represents something different"and that he could "pull off a significant part of NRM membership of Museveni loyalists."
However, Evelyn Anite, a lawmaker who speaks for NRM, told the AP news agency they expected Mbabzi's challenge to fizzle out.
Kizza Besignye was defeated by Yoweri Museveni in 2011
Uganda's Daily Monitor reported that the current NRM secretary-general, Justin Kasule Lumumba had described Mbabazi's declaration as "indiscipline."
Last week the opposition parties formed a coalition know as The Democratic Alliance, or TDA in short. They referred to that move as "the final push" against Museveni.
TDA says it will field a joint candidate for the election, pledging that if successful their candidate would serve only one term.
Members of the TDA include Uganda's main opposition party, Forum for Democratic Change (FDC), the Conservative Party, the Democratic Party, the People's Progressive Party (PPP) and Uganda Federal Alliance (UFA).
Daily Monitor said FDC secretary-general Nandala Mafabi responded positively to Mbabazi's declaration.
"This is good for democracy and as oppostion we welcome Mbabazi's candidature," he said.
In the last presidential elections in 2011, Museveni defeated his long time Kizza Besigye, who then leader of the FDC.
Besigye subsequently led repeated attempts at anti-government demonstrations, in which he was regularly arrested and held for a few hours before his release.