In the 1980s Daly was a member of the Labour Party as a teenager but was expelled alongside other members after being accused of being Trotskyists infiltrating the party using the tactic of entryism. She was subsequently a founding member of "Militant Labour", later known as the Socialist Party. In 1999 she was elected to Fingal County Council, a position she held for 12 years. Daly was elected as a Socialist Party TD for the Dublin North constituency at the 2011 general election.
"Since 2012, Daly has formed a close political association with Mick Wallace. After Wallace was condemned by left-wing TDs following the revelation his building company had avoided €2.1 million in taxes, Daly resigned from the Socialist Party in August 2012 in protest and redesignated herself as a United Left Alliance TD, before switching party again in 2015 to her current party Independents 4 Change."