Labour Party (UK) affiliated trade union

In British politics, an affiliated trade union is one that is linked to the Labour Party. The party was created by the trade unions and socialist societies in 1900 as the Labour Representation Committee and the unions have retained close institutional links with it.
Affiliated unions pay an annual fee to the Labour Party; in return, they elect thirteen of the thirty-nine members of Labour's National Executive Committee and fifty per cent of the delegates to Labour Party Conference. Local union branches also affiliate to Constituency Labour Parties and their members who are also individual members of the Party may represent the union as delegates on Labour Party structures.
Individual members may "opt out" of paying into a union's political fund which is used to finance the affiliation.
Since 1994, affiliated trade unions have organised themselves into TULO - The Trade Union & Labour Party Liaison Organisation, with a small number of staff to manage the relationship between the unions and the Party. A national TULO committee, with the unions' general secretaries, the Party Leader and Deputy Leader, General Secretary and NEC Chair and MPs' representatives, meets regularly to co-ordinate work and policy.
Until 1995, each union exercised a block vote at party conferences; since then, multiple delegates of a single union get an equal share of its voting allocation.
Affiliated unions.
As of April 2017, the trade unions affiliated to the Labour Party are:
The General Federation of Trade Unions (GFTU) represents its members, seven of the smaller unions, on many of the committees if they cannot send a delegate. In 2015, Unity merged into the GMB. In January 2017, the Broadcasting, Entertainment, Cinematograph and Theatre Union (BECTU) merged with Prospect, a trade union that represents certain grades in the civil service and other professionals. Because Prospect represents civil servants, they are politically neutral and so BECTU disaffiliated from the Labour Party as a condition of the merger. In January 2017, the Union of Construction, Allied Trades and Technicians (UCATT) merged into Unite.
Former affiliates.
During Tony Blair's leadership of the Labour Party, the RMT and Fire Brigades Union severed their links. However, the Fire Brigades Union re-affiliated to the Labour Party in November 2015.
Formerly, there were many more small trade unions in the UK, and many of them affiliated to the Labour Party. In 1946, the affiliates were: