A political storm is brewing between Istanbul's Mayor Ekrem Imamoglu and President Recep Tayyip Erdogan, as Erdogan continues to publically blast the opposition mayor with criticism.
"The mayor of Istanbul rubs shoulders with those who have links with terrorism in Diyarbakır," said Erdogan on Sunday at a rally of supporters in Trabzon, an electoral stronghold.
"Those who cannot take up a position against terrorism cannot be a mayor or a politician," he added.
Erdogan was referring to Imamoglu's visit to Diyarbakir, the main city in Turkey's predominantly Kurdish southeast.
The Istanbul mayor met last weekend with fellow mayors of Diyarbakir, Van and Mardin. All were removed from office last month by the Interior Ministry as part of a probe into links to the outlawed Kurdish rebel group the PKK.
Imamoglu strongly condemned the mayors' ousting as an attack on democracy. Analysts warn Erdogan is now setting his sights on the mayors of the main opposition CHP.
"I lot of people take this as a real threat," said international relations lecturer, Soli Ozel of Istanbul's Kadir, Has University. "A lot of people take what happened to the three mayors in the Southeast and members to what will happen to the cities where CHP and iyi Party [junior opposition party] party control."
In March, opposition parties handed Erdogan his worst electoral defeat, taking control of Turkey's main cities, including Istanbul and the capital Ankara.
The CHP's victory in Istanbul was the biggest blow to Erdogan's prestige, ending his 25-year domination of Turkey's largest and richest city.
Imamoglu's rise to political stardom was assured by successfully winning the mayorship with a landslide in June's rerun of the vote after Erdogan contested the narrow March victory.
Imamoglu is already using the powerful platform of the Istanbul mayorship to reset the political agenda. His high-profile Diyarbakir visit is seen as a move to consolidate support among Turkey's Kurdish vote, which was key to his Istanbul victory.
"Imamoglu broke tradition with his party by visiting Kurdish southeast and breaking bread with sacked mayors," said analyst Atilla Yesilada of Global Source Partners. "An alliance of sorts is jelling between CHP and HDP [pro-Kurdish party], which Erdogan must reverse if he wishes to cling on to power."
Imamoglu's politics of consensus even made inroads into Erdogan's religious conservative base — a significant political threat to the president.
The Istanbul mayor is playing down Erdogan's threats to remove him.
"Everyone should now know their limits," Imamoglu said Sunday.
Erdogan in the last few weeks, backed by pro-government media, has been ramping up his rhetoric against the Istanbul mayor.
The recent flash flooding of Istanbul while Imamoglu was on vacation drew swift condemnation by Erdogan and the media under his control.
"This can be the start of a process which can end with taking control of Istanbul and Ankara," said international relations professor Huseyin Bagci, of Ankara's Middle East Technical University.
"Erdogan has crossed a line [removal of Diyarbakir, Van and Mardin mayors] which I think he cannot step back. It's a power play. "
Financial as well as political considerations are also seen as a factor that could influence Erdogan's decision to move against the Istanbul mayor.
Last week, Imamoglu ended 357 million liras (about $61.5 million) of funding to foundations with close ties to Erdogan's family and inner political circle.
Among the organizations affected by the cuts include the Turkey Youth and Education Service Foundation (TURGEV), whose board includes Erdogan's daughter Esra. The Turkish Youth Foundation (TUGVA), has the president's son Bilal on its high advisory board.
Observers say the impact is being felt by the companies linked to Erdogan and his AKP Party.
Several pro-government media companies have laid off hundreds of workers, following Imamoglu ending lucrative advertising deals.
A source close to the presidency claims pressure from these powerful Istanbul companies linked to Erdogan had persuaded the president to force a rerun in the Istanbul mayoral election.
Analysts suggest Erdogan could be facing similar pressure from them to oust Imamoglu.
"He [Erdogan] seems to be decided not taking the risk, is more of the risk," said Ozel. "I suppose the AKP will not be able to ever win again in these cities [Istanbul and Ankara] or not for a long time. So he [Erdogan] thinks it's a risk worth taking he will do it. "
The Istanbul mayor is working hard to build on his broad political base, while at the same time introducing popular policies like a 24-hour subway service.
The removal of a still popular mayor, elected twice this year, is seen as potentially Erdogan's greatest gamble, threatening both political and financial turmoil.