Turkish President Recep Tayyip Erdoğan’s ruling AKP party appears set to suffer a nationwide setback against the main opposition CHP, preliminary unofficial results showed on Sunday. Erdoğan’s AKP is headed for defeat in all top five urban centres, including the largest metropolis Istanbul and the capital Ankara, unofficial results from state news agency Anadolu showed. Initial countrywide results gauge the race for mayoral seat for each 81 cities. This is the first time Erdogan’s AKP is fall behind in a countrywide poll in the more than two decades of his rule. Sunday marks the “first time si…