In 2010, the DA and ID formalized an agreement in which the ID would merge into the DA by 2014. This was prompted in part by the ID's disappointing result in the 2009 general election. As per the agreement, ID ceased to exist at the local level after the 2011 municipal elections with ID members running as DA candidates. DA won a large outright majority in the election, and ID leader Patricia de Lille, who had defeated Plato in an earlier internal election, became the new mayor. The party extended its lead even further to win a two-thirds majority of the seats on the City of Cape Town council in the 2016 municipal elections, and De Lille was thus sworn in to serve a second term