The president, who is chief of state and head of government, maintains strong executive power. The president heads the cabinet and is elected by popular vote every four years in a two-round run-off system. To win in the first round, a candidate needs at least 40% of the vote and to gain a 10-point advantage over the closest rival. Presidential powers increased considerably after changes to the constitution were agreed in a referendum in September 2008 under President Correa. This included permission for the president to run for immediate re-election for a second four-year term (previously, the constitution allowed multiple non-consecutive terms).