His father was long-serving secretary of the butchers' section of the Workers' Union of Ireland (WUI)), and a close associate of James Larkin.

On 1 July 1981, he was appointed as a Member of the European Parliament (MEP) for Dublin, replacing Michael O'Leary, who had resigned the seat after succeeding Cluskey as Labour leader.

The coalition government fell in January 1982 over a budget dispute, and Cluskey was re-elected to the Dáil at the February 1982 general election.

[5] When the coalition returned to office after the November 1982 election, Cluskey was appointed as Minister for Trade, Commerce and Tourism.

On 8 December 1983 he resigned as Minister due to a fundamental disagreement over government policy about the Dublin Gas Company.