What's next for Turkey's opposition after major election wins?

At just past midnight on Monday, re-elected Istanbul mayor Ekrem Imamoglu addressed jubilant crowds outside the city's municipality building, after his party delivered a substantial blow to the ruling party, marking one of their most significant defeats.

“Sixteen million Istanbulites have won – congratulations. There are no losers in this election,” he said, rolling up his sleeves and removing his tie – an apparent gesture to his willingness to return to work serving Turkey’s largest city. “The era will continue where every Istanbulite receives equal and fair service.”

The crowd whooped and cheered joyfully, some wearing headbands bearing the words, “Ekrem Imamoglu is one of us.”

Mr Imamoglu’s re-election as mayor of Istanbul was the biggest victory of a night of wins for Turkey’s main opposition party, the Republican People’s Party (CHP). It maintained or won control of six of Turkey’s biggest cities by population size – Istanbul, Ankara, Izmir, Bursa, Adana and Antalya.

“This is the biggest defeat Erdogan has registered in his political career,” said Murat Somer, a political-science professor at Ozyegin University.

Mr Imamoglu won Istanbul with 51 per cent of the vote, compared to 39.6 per cent for Murat Kurum, the candidate for Erdogan’s Justice and Development Party (AKP).

In the capital Ankara, popular CHP mayor Mansur Yavas was re-elected with 60 per cent of the vote, compared with the AKP candidate’s 32 per cent. Within Istanbul, CHP won control of important local districts too, including the tourist centre of Beyoglu, and Uskudar. The district on Istanbul’s Asian shore is symbolically significant as it is where Turkish President Recep Tayyip Erdogan casts his vote.

The election results are “a great success for CHP. We have won back all the metropolitan mayoralties and added on to them”, said Unal Cevikoz, a former CHP MP.

He put the AKP’s losses down to economic hardships: with inflation near 70 per cent and the Turkish lira slipping ever further against the US dollar and the euro. Turks have continued to struggle financially despite government measures put in place over the last year to try to fix the economy.

In Istanbul, Mr Imamoglu will preside over tens of thousands of employees, a multibillion dollar budget and the resources of Turkey’s cultural and financial capital for the next five years. He won on a campaign promising the end of a controversial canal project, providing low-cost food and transport and opening an array of sports and cultural facilities.

Observers attributed the CHP’s success in the local elections to its willingness to reform after its candidate, Kemal Kilicdaroglu, lost to Mr Erdogan in last year’s presidential elections. They said voters rewarded segments of the opposition that prioritised policy over internal squabbling.

“Voters appear to have rewarded those opposition actors who have been willing to self-critically reform themselves and come up with new ideas, new names, and candidates – the first actor among these is Istanbul mayor Ekrem Imamoglu,” said Prof Somer.

Voters celebrating Mr Imamoglu’s win are already looking to the mayor to compete in Turkey’s next presidential election scheduled for 2028.

“We want him [Imamoglu] to be president; he has united everyone,” said Simay, a 24-year-old doctor who asked that only her first name be published.

She cited Mr Kurum’s failings as a former government minister and religiosity as reasons for disliking the AKP’s candidate for Istanbul's mayor.

At the same time, voters sent a message of their discontent with current President Erdogan.

“Tayyip, resign! Tayyip resign!” chanted the crowds celebrating Imamoglu’s win.

The President will not heed the crowd’s chant and step down. But he acknowledged that his party had not done as well as hoped in a late-night speech at his party headquarters in Ankara. “We will turn the period until the next elections into a comprehensive accounting ground where we renew ourselves in every respect and make up for our mistakes,” he said.

The Istanbul defeat was a particular blow to Mr Erdogan, who launched his political career in the 1990s in the city and had hoped Mr Kurum would win the mayoralty back from the political opposition.

The difference between Mr Erdogan’s win in the presidential elections last year and the AKP’s losses in the local elections raise questions about the president’s political future and that of his party, which has no clear successor when he steps away from politics. The CHP, on the other hand, has a clear next generation in Mr Imamoglu and Mr Yavaş.

With 78.5 per cent of eligible voters going to the ballot boxes, Sunday's turnout for local elections held across Turkey was lower than in previous elections.

Observers say some of those who stayed at home were disillusioned AKP voters who wanted to warn the party about their disappointment in seeing few improvements to their quality of life despite continuing to vote them into power. Others voted for opposition candidates such as Mr Imamoglu.

AKP also lost votes to the conservative Islamist New Welfare Party (YRP), which took control of two provinces – Sanliurfa on the Syrian border and Yozgat in central Anatolia.

“YRP did a good job presenting itself as an address for AKP voters who did not want to vote AKP and differentiating themselves just enough from them,” said Seda Demiralp, a professor of political science at Işık University in Istanbul. “There are two issues they have been critical on – the government’s passive role in the Israel-Palestine conflict and on the economy.”

Votes from Turkey’s Kurdish citizens appear to have contributed to Mr Imamoglu’s win in Istanbul. The pro-Kurdish DEM Party fielded its own mayoral candidate in the city, who received just 2 per cent of the vote, suggesting that many of Istanbul’s millions of Kurdish citizens chose to vote for Mr Imamoglu instead of along ethnic party lines.

Mr Erdogan still has a tight grip on governance, controlling all branches of government and much of the media scene. He will retain his seat until the next presidential election in four years’ time.

“I think the opposition will realise that this [local election] success cannot be sustainable unless they also translate it into success on the national level,” said Prof Somer.