ISTANBUL (AP) — Mayoral elections are underway in 30 large cities in Turkey along with other municipal races Sunday that are seen as a barometer of President Recep Tayyip Erdogan’s popularity amid a sharp economic downturn in the nation straddling Europe and Asia.

More than 57 million voters were eligible to take part in choosing the mayors of major cities, 51 provincial capitals and 922 districts in Turkey. They also were casting ballots at 200,000 polling stations across the country to elect local assembly representatives, as well as tens of thousands of neighborhood and village administrators.

Economic prosperity provided Erdogan and his Justice and Development Party with previous electoral successes. With Turkey’s weakening currency, inflation at double-digit figures and food prices soaring, the conservative, Islamic-based ruling party could lose control of key mayors’ posts.

Opposition parties coordinated strategies and put forward candidates under alliances in an effort to maximize the chances of unseating members of the Justice and Development Party, known in Turkish by the acronym AKP.

A main battleground appears to be the capital, Ankara. Opinion polls suggested the candidate of an opposition alliance, Mansur Yavas, could end the 25-year rule of AKP and its predecessor. A former government environment minister, Mehmet Ozhaseki, is running for mayor under the banner of Erdogan and his nationalist allies.

Another closely watched mayoral election is in Istanbul. Erdogan began his rise to power as the city’s mayor in 1994 and has said at campaign rallies that “whoever wins Istanbul, wins Turkey.”

Erdogan named former Prime Minister Binali Yildirim to run against opposition candidate Ekrem Imamoglu in the Istanbul mayor’s race. The president spoke at six rallies in Istanbul on Saturday.

Erdogan has campaigned tirelessly for AKP’s candidates, portraying the country’s economic woes as an attack by enemies at home and abroad, and framed the municipal elections taking place across Turkey on Sunday as matters of “national survival.”

Gonul Ay, 38, said she voted for the ruling party and Yildirim in Istanbul because of his experience.

“I voted for the AKP for continuity and so that their services continue,” the homemaker said. “God willing, this crisis and chaos will be fixed and we’ll see healthier, happier days.”

Volkan Duzgun, 32, said he voted for opposition candidate Imamoglu.

“Everyone is either running against Erdogan or running for Erdogan,” he said. Duzgun added, “All elections have turned into a race against the one-man regime, and people we call the opposition is trying to carve out some breathing space.”

The ruling party accused Ankara mayoral candidate Yavas of forgery and tax evasion while also threatening to not accept results in the southeast if candidates with alleged “terror” links from the pro-Kurdish Peoples’ Democratic Party —the second-largest opposition group in parliament — win there.

Since 2016, Erdogan’s government has replaced elected mayors from the pro-Kurdish party in in nearly 100 municipalities, installing in their place government-appointed trustees and alleging the ousted officials had links to outlawed Kurdish militants.

The pro-Kurdish party is seeking to win back the offices. However, it strategically sat out critical mayoral races in major cities, including Istanbul and Ankara, with the aim of sending votes to a rival secular opposition party to help challenge Erdogan’s party.

Since the previous local elections in 2014, Turkish citizens have gone to the polls in five different elections. In last year’s presidential and parliamentary elections, Erdogan garnered 52.6 percent of the votes and his party and its nationalist ally won 53.7 percent of the parliamentary vote.

Sunday’s municipal elections are also a first test for Erdogan since he won elections last year that ushered in a new system that gave him wide powers.