Erdogan's push for more power: Who will vote against him?

On Sunday, the Turks will vote in a referendum on a proposed constitutional reform that would see the implementation of a presidential regime, greatly strengthening President Recep Tayyip Erdogan’s powers. It’s expected to be a tight race, even though polls currently predict a “yes” camp victory. Who are the people behind the main political groups opposing this change? Our correspondents went to meet them.