ISTANBUL (Reuters) - Immaculately coiffed with a camera-ready smile, Mustafa Sarigul's composure cracks a little as his campaign bus swings towards Istanbul's old city walls.
Two months before elections which could reshape Turkey's political landscape, the main opposition candidate for mayor of its biggest city is taking the fight to a bastion of Prime Minister Tayyip Erdogan's Islamist-rooted AK Party.
