Tunis - Beji Caid Essebsi, the 87-year-old ex-premier and leading opponent of the Islamists, said on Tuesday he will stand in Tunisia's presidential poll later this year, if he's "still alive".
"At the moment, my intention is to run" in the 23 November election, Essebsi told a news conference.
"[I say] for the moment, because nothing is certain in life. If I'm still alive on election day, obviously, I will do my best to be there," he said.
The octogenarian has already been nominated as the candidate of Nidaa Tounes, Tunisia's main secular party, which he heads.
A veteran of Tunisian politics, Essebsi was minister of the interior, defence and foreign affairs under the country's founding president Habib Bourguiba, and then parliamentary speaker under Zine El Abidine Ben Ali.
His critics accuse him of seeking to restore the regime of the deposed dictator, while his supporters say he is the only credible counterweight to the Islamist Ennahda party, which resigned this year after months of political crisis.
After months of negotiations among political parties, Tunisia's parliament last month approved 26 October as the date of the legislative election and 23 November for the first round of the presidential poll.
On Tuesday, Essebsi called for a one month extension of the voter registration process, which was due to be completed on 22 July.
About eight million Tunisians are eligible to vote, but only half that number registered in 2011, for the first poll after the uprising that toppled Ben Ali and sparked similar revolts across the region.
Before the Arab Spring uprisings, there were more elderly leaders in the region, with Egypt's ousted dictator Hosni Mubarak, now aged 86, leading the race by some distance.
If he were elected, Essebsi would claim that dubious title, being 10 years older than the oldest head of state still in power, Algeria's Abdelaziz Bouteflika.