ISTANBUL, Turkey -- Turkish Prime Minister Recep Tayyip Erdogan appeared to get a big boost from local elections Sunday, in a vote that he has framed as a referendum on his rule.

Erdogan wasn't on the ballots in the countrywide polls, but with about half of votes counted, Turkish newswires suggested that his party was significantly outstripping its results in the last local elections of 2009 and roundly beating the main opposition party.

The strong results would appear to strengthen the prime minister following a tumultuous corruption scandal.

In high-profile races for mayor of Istanbul and Ankara, incumbents from Erdogan's Justice or Development Party, better known by its Turkish acronym AKP, were in tight races, according to the early results. The Turkish elections board says more than 50 million people were eligible to vote.

Voter turnout appeared to be strong, with people forming long queues at polling stations. Although quality polling is hard to come by in Turkey, it was widely expected that the AKP will outstrip opposition parties Sunday, winning a plurality of the vote.

But how much of a plurality will matter. Erdogan's party has already been trying to lower expectations. His party has pointed to the 39 per cent they received in the 2009 local elections as a benchmark.

Erdogan and his party have dominated Turkish politics over the past decade in a period of great prosperity. The party came to power backed by a pious Muslim base looking for greater standing in a country that had favoured a secular elite. But AKP, whose party symbol is a light bulb, has also cultivated an identity of pragmatism and competency.

That image has been rocked by a corruption scandal, with a series of leaked tapes bringing down four ministers with revelations of bribe-taking and coverup. One tape allegedly involves Erdogan and family members, but he and his allies have rejected the allegations as a plot orchestrated by followers of U.S.-based Muslim cleric Fethullah Gulen, a former Erdogan ally who has split with him.

Erdogan has been suggesting at rallies of hundreds of thousands of supporters that the election will let the people decide if the tapes are significant.

"What the people say goes," Erdogan said after casting his ballot. The people's decision is (to be) respected."

Suzan Fraser in Ankara contributed.