Councillor Dr Arthur was first elected councillor for the
Colinton/Fairmilehead at the
2017 City of Edinburgh Council election as a member of the
Labour Party. He was re-elected in 2022. In May 2022, Dr Arthur was appointed the Transport and Environment Convener in the Labour Party's minority administration of the City of Edinburgh Council. He said at the time that the position would be interim and he would be standing down in October of that year following a council reshuffle. Dr Arthur went on to serve as the Transport and Environment Convenor until September 2024. His resignation as a councillor followed his election to the UK Parliament. As Transport and Environment Convenor in the Council, Arthur was instrumental in advocating a new north-south route for the tram, linking
Granton in the North West of the city to the BioQuarter in the South East. Dr Arthur was a strong proponent of the Roseburn route for the north-south line, stating it would link the tram with the Western General Hospital, along with other congestion-based benefits. This option was met with controversy due to concerns over displacement of cyclists and loss of biodiversity along the route. The consultation on the proposed routes ended in November 2025. During his convenorship, Dr Arthur also oversaw the ban on pavement parking in Edinburgh. The policy was designed to increase pavement accessibility for wheelchair users, those with mobility issues, the blind or partially sighted, and those pushing buggies. The ban introduced fines of £100 for pavement parking and covers all streets in the capital. The ban was praised by Guide Dogs and Living Streets UK. Since his election to Parliament, Dr Arthur has continued to raise the issue of pavement parking.
Member of Parliament In
July 2024, Arthur was elected Member of Parliament for
Edinburgh South West, beating the incumbent
Scottish National Party candidate
Joanna Cherry by 6,217 votes. In September 2024 he was 6th of the 20 MPs drawn in the
Private Members' Bill ballot. He chose to use the ballot slot to introduce the
Rare Cancers Bill focused on improving treatments for rare cancers, the bill is sponsored in the Lords by
Baroness Elliott. In response to widespread anti-social behaviour in his constituency on Bonfire Night 2024, Dr Arthur led a campaign to stop the sale of fireworks in supermarkets. The campaign was successful, and all major supermarkets ended their sale of fireworks in the south west of Edinburgh. In October 2024, he was elected as a member of the
Transport Select Committee. He is a member of APPGs including Parkrun, Eating Disorders and British Buses. ==Personal life==