 Opponents expressed concerns about the cost of the project and an anticipated increase in traffic congestion, particularly on residential side roads.The consultation - the largest ever held by Transport for London - was reportedly dismissed by Mayor Ken Livingstone as "unscientific", who instead cited a separate poll of 1,100 west Londoners which claimed a 54% backing for the tram.Another 2004 poll of 1,800 people, commissioned from ORC by the Greater London Authority, claimed 56% support for the tram.