McCubbin concentrated on the fishing industry, which employed many constituents and was profoundly affected by the European Union's Common Fisheries Policy.
At the 1994 election, McCubbin campaigned on a pledge to reduce unemployment, but was defeated by Scottish National Party candidate Allan Macartney.
He resigned in 1999 to seek selection as a Labour candidate for the Scottish Parliament, and also attempted to return to Europe when Allan Macartney died and a byelection was held.
He attacked the government of Tony Blair in letters to Scottish newspapers, and in March 1999 confirmed that he had left the Labour Party over the bombing of Iraq.
Later that year McCubbin helped to launch Scottish Left Review, a bi-monthly journal of left-wing politics; he has been a member of its Editorial Committee ever since.