Turkish President Recep Tayyip Erdogan says there was “illegality” in Istanbul’s local elections, after the country’s electoral body ordered them to be re-held.

“We sincerely believe there is… organised corruption and complete illegality,” he said on Tuesday.

The decision to re-run last month’s vote, which returned a slim win for the opposition, sparked protests on Monday.

The opposition CHP’s victorious mayoral candidate said it was “treacherous”.

The European Parliament has also said the decision to re-run the election on 23 June would end the credibility of democratic elections in Turkey.

Speaking at a parliamentary meeting of his AK Party, Mr Erdogan said that re-doing the vote was the “best step” for the country.

“We see this decision as the best step that will strengthen our will to solve problems within the framework of democracy and law,” he said.

He insisted there was “illegality” in the vote and said a re-run would represent “an important step to strengthen our democracy”.