New Democracy MEP Giorgos Papastamkos was rushed to hospital in Strasbourg, France, on Wednesday after fainting during a parliamentary session.
The 58-year-old, who is also European Parliament vice president, fell ill while presiding over a vote.
He asked for a break for “personal reasons” and then collapsed.
Three fellow European parliamentarians who are doctors by profession provided him with assistance until an ambulance arrived to take him to the hospital.
European Parliament President Martin Schulz said Papastamkos’s condition was serious.