TUNIS — Tunisia’s young democracy has endured many shocks since it emerged from the Arab Spring protests of 2011. But its presidential runoff this month may pose a new and embarrassing question: What happens if the winner is in jail?
In the first round of presidential voting last month, all the major-party candidates were knocked out, leaving two contenders: Kais Saied, a previously obscure law professor who claimed 18.4 percent of the vote as an anticorruption independent, and Nabil Karoui, a businessman and co-owner of a popular TV network, who won 15.6 percent.
Several polls before Sunday’s parliamentary elections showed Mr. Karoui’s new Qalb Tounes (Heart of Tunisia) party to be ahead. But with the presidential runoff a week away, Mr. Karoui is behind bars, awaiting trial on charges of tax evasion and money laundering.
“It is a unique situation in Tunisia,” Prime Minister Youssef Chahed said Friday in a television interview. As the presidential candidate of the Tahya Tounes party, he was eliminated in the first round.
“But the justice system is independent,” Mr. Chahed added, “and Nabil Karoui is not a political prisoner. He has charges against him. We are not happy with the situation, but we cannot interfere with the judicial system.”
Mr. Karoui’s supporters have accused Mr. Chahed and his party of orchestrating his arrest in August, after previously trying to amend the election law to prevent Mr. Karoui from running.
“This is a political decision, and the whole issue is political,” a lawyer for Mr. Karoui, Nezih Souei, said in an interview. “He became both a candidate for presidency and a candidate for his own freedom to be able to do his campaign.”
An appeals court on Tuesday rejected Mr. Karoui’s fourth request for a temporary release, a decision that “is also affecting his voters,” his lawyer said.
Mr. Souei said Mr. Karoui still had other avenues for appeal, but little time before next week’s runoff.
Current electoral law does not appear to account for the prospect of Mr. Karoui’s winning without first being released, his lawyer said.
“He has immunity as a president, but only when he takes an oath,” Mr. Souei said. “So what happens before, between the time he is elected and the proclamation of the results? Can he take an oath while in jail? All this remains unknown.”
The shape of the runoff reflects widespread despondency and anger in Tunisia, where unemployment above 15 percent and a 6.7 percent inflation rate means many people face stagnant or deteriorating standards of living.
Mr. Karoui has support mainly among poorer people with whom he has built a relationship through his Nessma TV network and a philanthropic organization, Khalil Tounes. Mr. Saied, his law-professor opponent, ran a campaign with almost no advertising, relying on an image of integrity and the votes of young people disillusioned with the political system.
The men’s success threatens to shatter Tunisia’s consensus governing model since 2011, in which conservatives and modernists have shared power.
Several parliamentary polls show Mr. Karoui’s Qalb Tounes a few points ahead of the religious conservative party Ennahdha, with the potential for what Youssef Cherif, head of Columbia Global Centers in Tunis, said could be a “really unbalanced” result.
Mr. Saied has no formal ally in the parliamentary elections, but two outsider groupings considered likely to support him are just behind Qalb Tounes and Ennahdha in the polls.
“We fear that the next Parliament will be even more scattered with new political forces, and this could lead to divisions and an incapacity to rule,” Mr. Cherif said.
Experts are also concerned about the legal limbo enveloping Mr. Karoui. If he wins, there are questions about how he will take office. And if he loses, his lawyers say, he is likely to contest the results in court on the grounds that he was denied an equal opportunity to compete. His inability to participate in campaign debates might be one example of that.
“The whole electoral process could be considered invalid because of this situation,” the head of the High Independent Authority for Elections, Nabil Baffoun, was quoted as saying in local news outlets. He added that he had been advocating for Mr. Karoui’s release.
The tight time scale further complicates matters. Presidential elections were originally scheduled for next month. But Tunisia’s first legitimately elected president, Béji Caïd Essebsi, died in office in July, and an interim president may serve only for 90 days.
Mohamed Ennaceur, the former speaker of Tunisia’s Parliament, will finish his mandate in the interim role on Oct. 24.
“We are facing a dead end, with a risk of political violence if the results get canceled,” Mr. Cherif said.
On Saturday, Mr. Saied offered his own unorthodox solution to the problem: His website announced that, to ensure equality of opportunity between the candidates, he would refrain from campaigning before the runoff vote.