Donohoe was elected to the House of Commons at the 1992 general election for the Cunninghame South constituency after the retirement of the previous Labour MP David Lambie. Donohoe held the seat with a majority of 10,680 votes, and continued as the MP until 2015, when he was defeated at the general election by Philippa Whitford of the Scottish National Party by 13,589 votes. He made his maiden speech in the House of Commons on 13 May 1992. In parliament he served as a member of the TransportSelect committee, in its various forms, from 1993 until 2005. He has been a member of the Administration Select Committee since the 2005 general election. In November 2008, Donohoe was one of eighteen MPs who signed a Commons motion backing a Team GB football team at the 2012 London Olympic Games, saying football "should not be any different from other competing sports and our young talent should be allowed to show their skills on the world stage". The football governing bodies of Scotland, Wales and Northern Ireland are all opposed to a Great Britain team, fearing it would stop them competing as individual nations in future tournaments. Donohoe opposes same-sex marriage and has stated that he will oppose the rest of his party and vote against the government bill to introduce "same sex marriage" in England and Wales. In the 2015 United Kingdom general election Donohoe lost his Central Ayrshire seat to Philippa Whitford of the SNP by a margin of 13,589 votes. After his defeat, Donohoe said that he was "disappointed" to lose but that there was a silver lining: "I'm of an age where I can now turn round with the greatest delight and tell people to "fuck off!" which I haven't been able to do for a hell of a long time in both my trade union life and also in this one. You have to take all sorts coming through the door and be kind, considerate and generous with your time and sometimes you wonder why. But at the end of it you're there and I've always made the pledge as an MP that I wasn't just there to represent the people who voted for me, I was there to help." After the Chilcot Report investigating the Iraq War was released, Donohoe stated he was "not convinced" it gave any fresh insight into the controversial decision to invade Iraq. Donohoe had voted for the invasion, but a year later he said he would have voted against had he known Iraq did not have weapons of mass destruction. Donohoe was knighted in the 2019 Birthday Honours.
Personal life
He married Christine Pawson in 1973 and they have two sons. He takes a particular interest in renationalising the British railway system. Donohoe is a serving Special Constable with the British Transport Police. He is also a devoted fan of the television soap operaCoronation Street. Donohoe's seat of Cunninghame South was abolished, and between 2005 and 2015 he represented the redrawn seat of Ayrshire Central. He is the secretary of RangersSupporters Club.