Original sentence: The election also saw the introduction of political parties into municipal politics, with both the Liberals and New Democrats running slates, with the Progressive Conservatives chose not to run as an organized slate despite is supporters having a majority of seats on the council prior to the election
Edited sentence: The Progressive Conservatives chose not to run as an organized slate, despite its supporters having a majority of seats on the council prior to the election.The election also saw the introduction of political parties into municipal politics, with both the Liberals and New Democrats running slates