TUNIS, Tunisia (AP) — Supporters of a jailed presidential candidate in Tunisia say a court's refusal to release him so he can campaign was a political decision.

Polls show Nabil Karoui is among the leading contenders in the Sept. 15 election. Karoui's campaign team said Wednesday it's "convinced its candidate is the first political prisoner" of post-revolutionary Tunisia.

Supporters urged voters to cast their ballots for Karoui on Sept. 15.

A Tunis court decided Tuesday it was "incompetent" to rule on whether to free Karoui. He was jailed Aug. 23 for an investigation of possible money laundering and tax evasion charges.

The co-owner of TV station Nessma TV, he is a leading candidate among 26 in the race.

Karoui founded the centrist Heart of Tunisia party, with fighting poverty among priorities.