Turkish President Recep Tayyip Erdogan’s AKP Party-led alliance won the municipal elections by 51 percent on March 31. The elections were seen as a referendum on Mr Erdogan’s leadership following an economic downturn in Turkey. The secularist opposition CHP party claimed victories in the capital Ankara, Izmir, and in Istanbul, where Mr Erdogan had once been mayor.
But an AKP representative on the electoral board, Recep Ozel, said the vote was invalid, as some electoral officials were not civil servants and some result papers had not been signed.
A re-run in Istanbul will take place on June 23. which has sparked criticism from the European Union and leading member states.
Hundreds of people protested in many districts across Istanbul on Monday by banging pots and pans and shouting anti-government chants.
Mr Verhofstadt, the Belgian leader of the liberal group in the European parliament, said this decision showed Turkey was “drifting towards a dictatorship”.
He added the re-run threatened to make continuing EU accession talks “impossible”.
Mr Verhofstadt wrote on Twitter: “This outrageous decision highlights how [President Recep Tayyip] Erdogan’s Turkey is drifting towards a dictatorship.
“Under such leadership, accession talks are impossible. Full support to the Turkish people protesting for their democratic rights and for a free and open Turkey!”
But Dan Hannan, a British conservative MEP, responded by calling his condemnation a “double standard” on Brexit in Brussels.
He tweeted: “Holding a second vote in Turkey is ‘dictatorship’. But holding a second vote in the UK is democracy?
“My point is about the double standard in Brussels,not about whether the Istanbul election should be re-run.
“For what it’s worth though, I am, as British Conservatives traditionally were, deeply Turcophile.”
Prime Minister Theresa May’s withdrawal deal between the UK and the EU has been rejected by MPs three times, meaning Brexit will now be delayed until October 31.
This has resulted in supporters of a second Brexit referendum arguing British voters should have a say on the final deal between the UK and Brussels.
An EU spokesperson called for Turkey’s electoral body to explain the decision to re-run “without delay”.
The EU’s diplomatic chief, Federica Mogherini, said in a statement: “Ensuring a free, fair and transparent election process is essential to any democracy and is at the heart of the European Union’s relations with Turkey.”
Opposition candidate Ekrem Imamoglu won the mayoral election but has now been stripped of his duties.
He described this as “treacherous” and his CHP party has accused election authorities of “bowing to pressure” from Mr Erdogan.