Downie began his political career as a Councillor for
West Fife and Coastal Villages and Health Spokesperson in the Labour-led Fife Council administration. He resigned from both following his election to parliament. In September 2023, Downie was among several politicians who went on a diplomatic visit to Israel funded by
Labour Friends of Israel.
2024–present Downie ran in the
2024 United Kingdom general election in the constituency
Dunfermline and Dollar under the Labour Party. He was one of several Scottish candidates to received donations from Baronet Gordon Dalyell during the election. In the 2024 general election, Downie flipped Dunfermline and Dollar from the
Scottish National Party to the Labour party. He received 20,336 votes, 8,241 more than the next highest scoring candidate. Following his victory he stepped down from his role as Health Spokesperson but planned to continue as a councillor. However he did not wish to be paid for the position. He announced his resignation on 4 September 2024. A
by-election was held on 28 November 2024, to fill the seat. In March 2025, Downie began a petition to have the
Competition and Markets Authority investigate possible price-fixing or anti-competitive tactics with gas prices in Dunfermline. == Political positions ==