Bahaa Hariri, son of Lebanon's former prime minister Rafik Hariri, declared his intention to join the battle "to take back the country" on Friday, days after his younger brother Saad, also a former premier, announced he was quitting politics.
Bahaa Hariri released a recorded message in which he said he would "continue the journey" of his father, who established the Hariri family as the dominant player in Lebanon's Sunni community before his assassination in 2005.
"Through partnership and solidarity, we will enter the battle to take back the country and the sovereignty of the country from its occupiers," he said.
Bahaa Hariri is a fierce critic of Lebanon's Hezbollah group, an armed Iran-backed Shiite movement that dominates the country's sectarian political system. He launched a cross-sectarian political movement, Sawa Li Lubnan, in November to contest the next parliamentary election, scheduled for May.
Saad Hariri took on his father's mantle as representative of Lebanon's Sunni community after the 2005 assassination. His withdrawal from politics on Monday, four months before the election, has added to the turmoil facing Lebanon amid a devastating financial crisis. He attributed his decision to factors including Iranian influence, which he said prevented positive change in the country.
In his message on Friday, Bahaa Hariri said: "The son of the martyr Rafik Hariri will not leave Lebanon, I am with you and very soon I will be among you."
After 15 years of managing his business empire from London, he told The National in November that his decision to enter Lebanese politics was prompted by the deadly Beirut port blast in August 2020 that devastated the capital and claimed more than 200 lives.
Bahaa Hariri has been at odds with his brother Saad over his decision to reach a political compromise with Hezbollah. Members of the group were implicated in the assassination of Rafik Hariri, including one who was convicted by a UN special tribunal. Hezbollah denies any involvement in the killing.
Saad Hariri said on Monday his decision aimed to spare Lebanon civil war but had cost him his fortune and "even brothers".
Mohanad Hage Ali of the Carnegie Middle East Centre said Bahaa Hariri's message was "a signal that he will not allow a void in Sunni politics, that he is stepping in to carry the mantle".
"At the same time it is very difficult to see him filling the void, unless there is regional backing and solid financing behind him. If he is willing to spend money on the Sunni scene, perhaps he might have a chance," he told Reuters.