Anderson was first elected as a city councillor in 1998, representing the Abercromby ward. In 2003, he became the Leader of the Labour Group on Liverpool City Council, and in 2010 became the Leader of the Council, when Labour gained a majority of seats in the city. Previously he was on the board of the Liverpool Culture Company, a group involved in developing a programme of events for Liverpool's year as European Capital of Culture in 2008. However, he resigned this position in 2007 after stating his concern at the lack of community involvement in planned events, alleging that an elitist attitude was developing among the board. Anderson was, along with Liverpool RiversideMPLouise Ellman, involved with the campaign to free Michael Shields after his arrest and subsequent imprisonment in Bulgaria in 2005. In opposition, Anderson had been critical of the joint venture between British Telecom and Liverpool City Council called LDL. However, one of his first moves on becoming Council Leader was to appoint David McElhinney as temporary Chief Executive of the Council for the six-month period when the Council was renegotiating its contract with BT. McElhinney was Chief Executive of LDL at the same time. Cherie Booth QC was engaged to provide legal advice regarding the obvious potential for conflict of interest. The LDL contract was extended, although this was subsequently terminated when it came to light that McElhinney's payments from another council were under investigation. McElhinney and others were arrested as part of an ongoing investigation into allegations of conspiring to pervert the course of justice and intimidating witnesses. Anderson was interviewed by police under caution in November 2017. In April 2015, Anderson was involved in a legal dispute with Chesterfield High School, claiming unfair dismissal from his role as social inclusion mentor. It transpired that he had continued to receive an annual salary of £4,500 from the school in his working absence. The case for unfair dismissal was lost and Chesterfield requested that Anderson pay back a portion of the money he had received. The case attracted press attention when the judge revealed that Anderson had used Liverpool City Council lawyers to work on it despite its being a private matter. In December 2015, Anderson was appointed as Leader of the Liverpool City Region Combined Authority. This was not a conventional election, but a joint decision by council leaders of neighbouring local authorities. In May 2016, he announced his intention to run for the Labour Party nomination for the Mayor of the Liverpool City Region position. In the selection contest, he finished second to then-Liverpool Walton MP Steve Rotheram, who went on to win the election in May 2017. Anderson continued in his position as the Mayor of Liverpool. In May 2017, Anderson put himself forward for selection as a Labour candidate to be the MP for the Liverpool Walton constituency, but lost out to then-Unite the Union official Dan Carden. He issued a statement claiming, "Today we were reminded that the Labour Party is not always a meritocracy... after there will be more to say."
