Tunisia's electoral commission said Wednesday the country's presidential election runoff would take place on October 13 despite calls to postpone the vote by the party of a jailed frontrunner.ISIE said campaigning would kick off on Thursday for the second and final round of voting, which will see imprisoned media mogul Nabil Karoui face off against independent law professor Kais Saied."ISIE can neither advance nor postpone the date of the elections under the constitution," commission head Nabil Baffoun said.The spokesperson for Karoui, who has been detained since August 23 on charges of money laundering and tax evasion, had called on Tuesday night for a suspension of the vote as long as the candidate remains behind bars.That came as Tunisia's court of appeal rejected a fresh request for Karoui's release. ISIE, international observers and political leaders have called for Karoui to be allowed to campaign fairly."We have made every effort to ensure equal opportunities," Baffoun said."We sent letters to the justice ministry, the prosecutor general and even the judge in charge of the case to give Nabil Karoui the opportunity to speak in the media, or even to release him."The timing of Karoui's arrest, 10 days before the start of campaigning, raised questions about the politicisation of the judicial process.Despite the legal proceedings, Karoui's candidacy was approved by ISIE and he campaigned by proxy via the Nessma television channel he founded and through his wife.After the first round of voting on September 15, Saied led with 18.4% of votes, according to ISIE, with Karoui in second with 15.6%.