In the 1968 federal election, he was returned as Canada's sole Liberal-Labour MP, although he remained in the Liberal caucus.
The Liberal-Labour label was a reflection of a longstanding tradition in the riding of Kenora—Rainy River aimed at deflecting votes from the New Democratic Party, rather than as a mark of political dissent.
After the 1972 election, Reid was redesignated as a Liberal MP and became parliamentary secretary to the President of the Queen's Privy Council for Canada, and worked on issues such as improving the access of MPs to government records.
He then represented Canada on the Organization for Security and Co-operation in Europe's Mission to Bosnia and Herzegovina, and was also a member of the Provisional Election Commission responsible for writing and implementing an Election Act.
He was also an advisor to the Chief Electoral Officer on UN Transitional Administration in Eastern Slovenia.