ISTANBUL — The two main contenders for Istanbul mayor squared off on live television in a rare political debate late on Sunday. The city is gearing up for a controversial do-over election after the opposition candidate’s upset victory in March was nullified.

People from across Turkey tuned into the broadcast of former Prime Minister Binali Yildirim, who is on the ruling Justice and Development Party (AKP) ticket, and the opposition’s Ekrem Imamoglu, a former district mayor for the Republican People’s Party (CHP), in the first election debate in Turkey since President Recep Tayyip Erdogan’s party came to power in 2002 and discarded the ritual.

The discussion was largely cordial — including an exchange of Father’s Day gifts at the outset and posing for a photo with their spouses at the conclusion — but at points became tense, with both men frequently accusing the other side of lying.

Much of the debate went to relitigating the Supreme Electoral Council (YSK) decision to cancel the first election, with Yildirim arguing votes cast for him in March had been misattributed to Imamoglu. “This is theft,” he said. “Some strange things happened during the count, casting doubt” on the outcome.