MEPs have now been joined by the Commissioner responsible for EU enlargement negotiations, Johannes Hahn, to discuss the results of the constitutional referendum in Turkey earlier this month.
President Recep Tayyip Erdogan narrowly won the vote to hand himself new powers.
The role of president used to be a largely ceremonial position but Erdogan supporters have argued a more executive presidency will modernise the country.
Opposition parties and the Organization for Security and Co-operation in Europe (OSCE) have complained about voting irregularities ahead of the poll.
The EU Commission has urged President Erdogan to seek the “broadest possible” consensus on how to implement the results of the vote.