Kemal Kilicdaroglu, backed by a six-party opposition alliance, says if he wins he will bring freedom and democracy to Turkey, whatever it takes.
“The youth want democracy,” he told the BBC. “They don’t want the police to come to their doors early in the morning just because they tweeted.”
He is the Islamist leader’s main rival in elections on 14 May and has a narrow lead in opinion polls. This tight race is expected to go to a second round two weeks later.
Currently Turks can go to jail for “insulting the president.” Many have.
“I am telling young people they can criticize me freely. I will make sure they have this right,” says the 74-year-old, who leads the main opposition Republican People’s Party (CHP).
Some of Mr Kilicdaroglu’s supporters fear for his safety but he says it comes with the territory.
“Being in politics in Turkey means choosing a life with risks. I will walk my path whatever Erdogan and his allies do. They can’t put me off. They can’t scare me. I made a promise to this nation.”
President Erdogan, 69, has mocked his rival in the past saying he “couldn’t even herd a sheep.” But he’s harder to dismiss now.