Following in the footsteps of her father, she entered politics and became Chairman of Argyll Liberal Association from 1973 to 1976, and then vice-Chairman of the Scottish Liberal Party from 1977 to 1979. She stood as Liberal candidate for Argyll and Bute three times, losing in 1979 and 1983, but ultimately defeating Conservative minister John Mackay to secure election as Member of Parliament at the 1987 general election, becoming the Liberals' only female MP. She took the oath of allegiance in the House of Commons in Gaelic, and joined the Liberal Democrats on the party's formation in 1988. She increased her majority in the next two general elections, gaining the confidence of the voters in her scattered constituency of peninsulas and islands. She was a Liberal Democrat spokesman on transport and rural development from 1987 to 1988, on women's issues from 1988 to 1994, and on Scotland from 1988 to 1997. She was an advocate of home rule for Scotland and the promotion of and development of the Scottish Gaelic language. She was also chair of the Scottish Liberal Party from 1992 to 1993. She was appointed a member of the panel of chairmen by SpeakerBetty Boothroyd in her last term in the Commons, from 1997 to 2001. She supported the campaigns to end submarine operations of the Royal Navy and United States Navy in the Firth of Clyde, to hold another inquiry into the Chinook crash on the Mull of Kintyre in 1994, and the successful bid for the residents of Gigha to buy their own island. In 1992 Ray Michie became a member of the House of Commons Select Committee on Scottish Affairs. Later, she also became a joint Vice-Chairperson of the Parliamentary Group on the Whisky Industry. She stood down from Parliament at the 2001 general election, being replaced by Alan Reid. She was made a life peer as Baroness Michie of Gallanach, of Oban in Argyll and Bute on 14 July 2001. She was the first peer to pledge the oath of allegiance in Gaelic when being introduced to the Lords. At different points in her career, she was Vice-President of the Royal College of Speech and Language Therapists, Honorary Associate of the National Council of Women of Great Britain, and Honorary President of the Clyde Fishermen's Association, and also held honorary positions in the An Comunn Gàidhealach, the Scottish National Farmers' Union and the Scottish Crofting Foundation, and was a participant in the early days of the Scottish Constitutional Convention. She chaired the West Highland Health Services Solutions Group. In August 2007 she was appointed to the Scottish Broadcasting Commission established by the Scottish Government. Before the Commission was able to report Michie died at her home in Oban after receiving treatment for cancer. She died two days after her Liberal Democrat colleague in the House of Lords, Richard Holme. She was survived by two daughters, having been predeceased by her husband and a third daughter.