He founded and led the pro-Scottish Home Rule Scottish Labour Party in 1976, continuing as MP for South Ayrshire until he lost the seat in 1979.
[2]: 411 He served as a member of Ayr Town Council from 1962 to 1970, and was Head of Organisation and Social Services at the Scottish Trades Union Congress (STUC) from 1968 to 1970.
[2]: 412 Sillars was elected at a by-election in 1970 as the Labour Party Member of Parliament (MP) for South Ayrshire, quickly establishing a reputation as an articulate, intellectual left-winger.
The formation of the SLP was inspired primarily by the failure of the then Labour Government to secure a Scottish Assembly with strong executive powers.
[12] Having failed to win the Linlithgow seat from Tam Dalyell of the Labour Party at the 1987 general election, Sillars was chosen to be the SNP candidate for the Glasgow Govan by-election, held on 10 November 1988.
The 1992 general election proved a disappointment for Sillars personally; as he lost his Glasgow Govan seat to Ian Davidson of the Labour Party.
[13] It was at this time that Sillars made his famous comment that "Scotland has too many ninety-minute patriots whose nationalist outpourings are expressed only at major sporting events".
[17] Unlike his wife, Sillars called for abstention on the 1997 Scottish devolution referendum,[18] He accused Salmond of having no strategy for full independence and claimed the referendum was a fraud as "the SNP says it is a stepping stone to independence and Scottish Secretary Donald Dewar insists it will strengthen the Union", adding "Abstention is the best form of contempt".
"[18] In June 2004, Sillars called for the resignation of John Swinney as SNP leader and also claimed that the party's acceptance of devolution had been a tactical blunder.
Not because they're dummies, but the Scottish media hardly gives them any coverage from a Westminster point of view, so the people in the big league, they don't really count.
"[13] On 3 March 2022, the Daily Record revealed that Sillars had donated £2,000 to Labour MSP Jackie Baillie during the 2021 Scottish Parliament election campaign.
He told the BBC that he was "extremely disappointed" in Sturgeon for "adopting the same tactic as Cameron and company, which is to try to drive people into the Remain side through unjustified fear".
[25] Sillars also dismissed SNP MP Joanna Cherry's suggestion that the UK would no longer have access to trading with the EU's free market.
"[32] Sillars told an Alba Party meeting in July 2023 that Scottish independence supporters were "in no position to win" in proposed second referendum.
[33] On 26 March 2021, Sillars backed Alex Salmond's new Alba Party, saying: "This is a very welcome development as it gives the independence voters a party that is not the SNP – which many, including me, with justification, believe is tainted with political corruption, and which is grossly incompetent in a whole range of its activities from building ferries to building hospitals, and boasting about being the Saudi Arabia of wind, without creating jobs.
'"[35] Following the defeat of the SNP in the 2024 United Kingdom general election, Sillars described John Swinney's leadership as "a busted flush" and Nicola Sturgeon as "Stalin's wee sister".