After months of debate, Turkey's opposition parties agree to nominate secular opposition leader Kemal Kilicdaroglu as their joint candidate against President Recep Tayyip Erdogan in May polls.

A last-ditch deal aimed at averting a split of the opposition vote will see CHP chief Kemal Kilicdaroglu name the popular mayors of Istanbul and Ankara as vice presidents should he end Erdogan's two-decade rule.

The soft-spoken 74-year-old from Turkey's long-marginalised Alevi community says that the "the door" of the alliance "is open to everyone who shares our common Turkish dream.... regardless of belief, thought, ideology or identity."