The editor of a leading Turkish newspaper has resigned ahead of today's presidential election after Prime Minister Tayyip Erdogan criticised news coverage by the paper's media group.

Rights groups are concerned about government pressure on the Turkish media. Reports linked Friday's departure of Enis Berberoglu from the Hurriyet daily to such pressure, but the paper said he left of his own accord. Erdogan is poised to become Turkey's first popularly elected president in the election, but his grip on power has raised fears of authoritarianism.