Polling stations will soon open across Turkey for municipal elections to decide which of the main rival parties will control the country’s biggest cities. Sunday’s vote follows last year’s parliamentary and presidential elections in which incumbent Recep Tayyip Erdoğan extended his rule after two decades in power. The poll in Turkey’s largest city Istanbul as well as capital Ankara, among other industrial hubs, will be watched closely. The candidate of the secular Republican People’s Party (CHP), current Istanbul Mayor Ekrem Imamoğlu, is seeking to be elected for another five-year term. In 201…