Tunis, Reuters—Tunisia will hold the run-off of its first democratic presidential election on December 21, between incumbent Moncef Marzouki and Beji Caid El-Sebsi, veteran leader of secularist party Nidaa Tounes, electoral authorities said on Monday.

The vote for Tunisia’s first directly elected president marks the final step in the North African state’s transition to full democracy following the 2011 revolution.

EL-Sebsi narrowly beat Marzouki in the first round of the presidential election—the first since Tunisia’s 2011 uprising that toppled autocrat Zine El-Abidine Ben Ali and inspire the Arab Spring revolts. But the two front runners failed to win enough votes to avoid meeting again in the December run-off.

“The run-off will be held on December 21, and the electoral campaign will start December 9 through December 19,” Chafik Sarsar, the head of Tunisia’s electoral commission told a press conference.

Islamist party Ennahda, which won the first parliamentary election after the revolution, did not field a candidate for the presidential vote. But its supporters may be key in deciding who wins the run-off.

A former Ben Ali-era official, EL-Sebsi, 87, has cast himself as an experienced statesman with the skills to manage Tunisia’s economy and security, dismissing critics who worry about the return of old regime officials.

Marzouki, a rights activist, says the return of officials from Ben Ali’s one-party rule would erode the revolution that ended Ben Ali’s regime.

But Marzouki’s critics tie him to the Islamist-led government that took office in 2011 and that critics blame for mishandling the economy and security. It was forced to hand over to a technocratic government in January following a crisis over the killing of two secular leaders by Islamist militants.

Both candidates will now seek support from the range of Islamist, liberal and left-wing parties who fielded candidates. Key will be who wins votes from supporters of Ennahda and the left-leaning Popular Front, both well-organised movements.

After Islamist and secular rivals overcame the crisis last year and approved a new constitution, Tunisia has been held up as a model of democratic change and compromise in a region where neighbors like Libya are caught up in turmoil.