There are two European Parliaments. One in Brussels, Belgium, and one in Strasbourg, France.
766 MEPs and over 3000 members of staff travel every month from Brussels to Strasbourg for the chamber's plenary sessions.
MEPs say this monthly shuttle costs over €150 million, approximately 10% of the Parliament's yearly budget and almost 19000 tones of CO2 emissions.
In a bid to save money, time and the environment, the Parliament now wants to decide when and where it meets.