[7] Leaving school with three A-levels, in history, economics and general studies,[8] he began his working life on the Canada Dock, part of the Port of Liverpool.

[10] He was involved in unionising the white collar staff in the Liverpool docks among whom previously there had been an absence of trade union organisation.

[10] During the 1980s he became a close friend of Tony Mulhearn and Derek Hatton, then deputy leader of Liverpool City Council, and supported the Militant tendency.

[11][12] In 2007, he was appointed as the Assistant General Secretary for Industrial Strategy of the Unite the Union, a merger of the T&GWU and Amicus.

[13] In a speech at the 2010 Durham Miners' Gala he said political developments in Cuba and Venezuela should be better known, and suggested the reason they were not was because of "the fear of the good example".

[14] However, in March 2012 the industrial correspondent of the Press Association, Alan Jones, distinguished McCluskey during the BA dispute from the former National Union of Mineworkers (NUM) leader Arthur Scargill: "I think he's more willing to cut a deal".

[3] Labour politician Jon Trickett told George Eaton in 2016: "He got to the top through force of personality, intellect and organising skill".

[9][15] He argued in June 2016, that the changes made by those governments have "left the lowest paid and the most vulnerable workers in our society in dire straits".

On 21 November 2010, it was announced that McCluskey had been elected to the post, beating Jerry Hicks, Les Bayliss and Gail Cartmail.

[20] Simpson retired in December 2010, and Woodley followed shortly after that, leaving McCluskey to take office as the General Secretary on 1 January 2011.

[13] In December 2010, McCluskey wrote in The Guardian that "there is no case for cuts at all", the government's "austerity frenzy" being "whipped up for explicitly ideological reasons" to complete "Thatcherism's unfinished business by strangling the welfare state".

[24] In an April 2013 interview for the New Statesman, McCluskey urged Miliband to drop three "Blairite" shadow ministers from his frontbench team.

[34] McCluskey later termed the events of June and July 2016 concerning Corbyn's leadership of the Labour Party as a "crazy vote of no confidence, this mass resignation" and "this coup attempt" in an interview with Decca Aitkenhead of The Guardian.

[47][48][49] McCluskey defended the building project, describing it as a “sensible investment of members’ money, resulting in a world-class facility that will return an income for our union for generations to come”.

After moving to the T&GWU lead office in London, McCluskey had a child with Jennie Formby in 1991; both names are listed on the birth certificate.