A month after local elections which saw it lose control of Turkey's two largest cities, officials in President Tayyip Erdogan's AK Party are questioning an alliance with nationalists which some blame for one of its biggest electoral setbacks. Under a deal between Erdogan's Islamist-rooted party and the smaller Nationalist Movement Party (MHP), the nationalists fielded no mayoral candidate in the capital Ankara or Istanbul in the March 31 vote, and the AKP stood aside in other regions. But the deal failed to prevent the secularist Republican People's Party (CHP), which had a similar pact with other smaller opposition parties, winning the mayoralty in both cities, ending a quarter century of control by the AKP and its Islamist predecessors. The AKP is still challenging its narrow loss in Istanbul, Turkey's largest city and business hub where Erdogan himself served as mayor before the party swept to power nationally in 2002. It has dominated Turkish politics ever since. While the Istanbul appeal drags on, the rare defeat has prompted questions within the party over campaign strategy. Although the alliance helped them win a majority of votes nationwide, AKP officials say it has delivered limited benefits. "The MHP gained a lot from this alliance, more than us," a senior official at the AKP headquarters in Ankara told Reuters. Another AKP official said the MHP's 71-year-old leader Devlet Bahceli, once a staunch critic of Erdogan, was an unpredictable ally. The AKP relies on the MHP for its parliamentary majority, meaning any break in the pact would leave it looking for new partners - a significant challenge after Erdogan's blistering criticism of his opponents during the campaign. But that has not stopped talk of a split. The senior official said that if Turkey's electoral board rules against a re-run of the Istanbul vote requested by the AKP, there was little incentive to maintain the alliance. "Depending on the decision, the fate of the alliance will be determined. It is not possible to say where the alliance will go in the short-term, but the fracture has become noticeable now," he said. An MHP official said that while differences with the AKP were emerging in public, the nationalists would not be the side to end what the parties have called their "People's Alliance". Bahceli said he remained committed to the pact. "This is our basic choice, our national and strategic goal," he said in a statement on Wednesday. "There is undoubtedly no need to search for other alliances." The stunning setbacks for the AKP in Ankara and Istanbul prompted sharp public criticism last week from a politician once at the heart of Erdogan's administration. Former AKP prime minister Ahmet Davutoglu condemned his party's alliance with the nationalists, saying it was damaging "both in terms of voter levels and the party's identity". Davutoglu, who served as premier between 2014 and 2016, also slammed the AKP's economic policies, media restrictions and the damage he said it had done to the separation of powers and Turkey's institutions. Since the election, Erdogan has appeared to downplay the significance of the MHP, pointing to its 7 percent share of the vote. Bahceli said the remarks were "unfair and unjust", given that his party had chosen not to stand in Turkey's three largest cities. After CHP leader Kemal Kilicdaroglu was physically attacked at a soldier's funeral last month, Erdogan struck a more conciliatory tone with a call for unity. "On matters that concern the survival of our country, we must move all together with 82 million as the TURKEY ALLIANCE, putting aside our political differences," he tweeted. Analysts say his reference to national unity may be largely rhetorical, and the opposition says it rings hollow after he repeatedly accused the CHP and its Iyi (Good) Party allies during the election campaign of supporting terrorism. "Some people within the AKP are doing self-critism. This bothers Erdogan. How could a person who can't even tolerate self-criticism within his own party preach democracy?" CHP Deputy Chairman Muharrem Erkek said. "His own words show he is not sincere in the 'Turkey Alliance' rhetoric." — Reuters