Amicus was the United Kingdom's second-largest trade union, and the largest private sector union, formed by the merger of Manufacturing Science and Finance, the AEEU (Amalgamated Engineering and Electrical Union) agreed in 2001, and two smaller unions, UNIFI and the GPMU. Amicus also organised in both parts of Ireland and was affiliated to the UK Trades Union Congress, the Irish Congress of Trade Unions and the Scottish Trades Union Congress.

The Amicus Curiae Brief: From Friendship to Advocacy
Amicus Curiae and the Role of Information at the Supreme Court
The Influence of Amicus Curiae Briefs on the Supreme Court
Amicus or adversary: platelets in lung biology, acute injury, and inflammation
Amicus brief for the case of State of New Jersey v. Michaels presented by Committee of Concerned Social Scientists.
Interest Group Success in the Courts: Amicus Participation in the Supreme Court
Gonzales v. Oregon. Brief for the Cato Institute as Amicus Curiae in Support of Respondents
Plateletpheresis efficiency: a comparison of the Spectra LRS and AMICUS separators
Friends of the Court: Examining the Influence of Amicus Curiae Participation in U.S. Supreme Court Litigation
Laboratory Hybridization of Stator beali and S. Limbatus, with New Host Records for S. Limbatus and Mimosestes amicus (Coleoptera: B...