She was first elected as an MSP in 1999 for the newly created Glasgow Maryhill constituency,[4] a seat she held until 2011 when Glasgow Maryhill was merged with other constituencies to form the Glasgow Maryhill and Springburn constituency. She won the 2011 Glasgow Maryhill and Springburn election but lost her seat in 2016[5] to Scottish National Party(SNP) member Bob Doris.[6]
After being elected as MSP for Glasgow Maryhill in May 1999, she was Deputy Presiding Officer of the Scottish Parliament from 1999 until 2001 and as a member of several of the Parliament's Standards and Procedures Committees.[7]
Ferguson was elected to the United Kingdom Parliament at the 2024 general election, defeating SNP incumbent Carol Monaghan of predecessor seat Glasgow North West.[10] Before that, she was first runner-up to Monaghan in Glasgow North West in 2019.[11]