Tunisia’s moderate Islamist Ennahda Party, which controls 30 per cent of the seats in the country’s parliament, announced it would be supporting Qais Said in the presidential election run-offs expected to take place in October.

The party’s shura council, its executive body, called on Tuesday for Tunisian voters to vote for the 61-year-old law professor who came in first in the first round of the elections with 18.4 per cent of the vote.

The date for the run-off hasn’t yet been announced, but Tunisia’s Higher Elections Authority, said it would be held by 13 October.

The other candidate, TV magnate and businessman Nabil Karoui, 56, who finished second with 15.6 per cent of the vote in the first round, has been in prison since August on charges of tax evasion and money laundering.

 Abdelkarim Zbidi, Tunisia’s defence minister, who finished fourth in the first round, called for Karoui’s release on Monday “to ensure equal opportunities for the candidates.” He said that any elections that do not guarantee these principles are “discredited and constitute a flagrant violation” of the constitution.

Zbidi was echoing calls to address the unusual situation of Karoui, who has not been sent for trial and remains incarcerated, as Tunisians ponder whether should be their next president.

Nabil Baffou, president of the Higher Elections Authority, said that the release of Karoui was necessary to guarantee equality of opportunity between the candidates in the second round. “The whole electoral process is in danger of being called into question,” he said on Monday.

Zbidi, who like Karoui and the other leading candidate Prime Minister Youssef Chahed hails from the secular Nedaa Tunis Party, which endorsed him in the first round instead of Chahed, also asked the premier to resign, accusing him of contributing to the country’s worsening economic situation and the rise of unemployment.

Tunisia’s state-run TV said that the Independent Higher Authority for Audiovisual Communication, the regulator, had given permission to allow Karoui to address the electorate and participate in the debates scheduled for the second round of the elections.

It is unclear whether he will be transported to the studios recording the debates or broadcast direct from prison.

In a written interview with the US Associated Press via his lawyer, Karoui said he was “reasonably optimistic” about winning the elections. “Of course we have a chance” he said, “because it’s a second round and both candidates will restart from scratch.” Karoui said he had celebrated his qualification for the run-off last week with his cellmates.

Karoui, who wears designer suits and has positioned himself as an advocate for the poor, said he wanted to be released to be able to campaign on an equal footing with his adversary. He denounced a “serious denial of justice and democracy” in Tunisia and added that this was “against the will” of the people who had voted for him.

Said, a little-known professor of constitutional law with no political experience, kept a low profile during the campaign, and he was not expected to make it through to the run-offs by observers who focused instead on Zbidi, Cherif and Ennahda candidate Abdel-Fattah Mourou.

Nicknamed “robocop” for his staccato speech, controlled emotions and command of fusha (literary) Arabic, Said ran his campaign by relying entirely on volunteers. In a TV interview prior to the elections, he said he had collected the required 10,000 dinars to register as a candidate from his extended family while contributing only 50 dinars from his own pocket.

Karoui, a controversial figure often referred to in the Western press as “Tunisia’s Berlusconi” in a reference to former Italian prime minister Silvio Berlusconi, made his name through his TV channel Nesma, which he has used to promote his political ambitions. By broadcasting the activities of his charity and projecting an image as an anti-establishment figure, Karoui has seen his popularity soar within Tunisia’s poorer regions.

His party described his arrest as having been “politically motivated” and accused front-runner Chahed of orchestrating the arrest. Karoui’s wife also took to the campaign trail after he was jailed.

The elections, however, saw a low turnout on the first round at 45 per cent, down from the 64 per cent in the country’s first democratic elections in 2014 after the fall of the former Ben Ali regime.

The powerful Tunisian General Labour Union (UGTT) denied rumours that it would support a candidate.  In a press release on Monday, the union’s secretary-general reaffirmed its neutrality between the two candidates.