Turkish President Tayyip Erdogan addresses his supporters at the Presidential Palace in Ankara, Turkey, April 17, 2017. REUTERS/Umit Bektas

ANKARA (Reuters) - Turkey’s High Electoral Board (YSK) will on Wednesday evaluate complaints and appeals for annulment of Sunday’s referendum on boosting powers of the presidency, broadcaster NTV cited the head of the board as saying.

The main opposition began a battle on Tuesday to annul the referendum which handed President Tayyip Erdogan sweeping new powers, while the bar association and an international monitor said an illegal move by electoral authorities may have swung the vote.