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Trade Unions

At present just under a quarter (23.5%) of UK employees are union members, although union density is much higher in the public sector (52%) than the private sector (13%). There is only one union confederation in the UK, the TUC, and individual unions are fully independent. More than half of trade unionists in the TUC are in the three largest unions, which have grown through mergers.

There are 6,754,197 union members in the UK, according to figures for 2019 and 2018 provided by the unions themselves.[1] Figures from the annual official Labour Force Survey, which excludes non-working members, show a total of 6,798,00, union members in employment in 2019, of whom 6,440,000 were employees.[2] (The closeness of the figures from the Labour Force Survey and the unions themselves reflects the fact, first, that the vast majority of union members are in employment – there is no tradition of unions having a large number of retired members – and second, that legislation passed in 2014 requires unions with more than 10,000 members to have their membership numbers certified by a qualified independent person.[3]


These membership figures mean that just under a quarter (23.5%) of all UK employees are union members. This is a very similar figure to that in the ICTWSS database of industrial relations statistics, which estimates union density at 23.4% in 2018.[4]


The vast majority – 5,421,895 in January 2020 – belong to the 48 unions affiliated to the TUC,[5] the only trade union confederation in Britain. The TUC does not operate in Northern Ireland. Unions operating in both Britain and Northern Ireland are frequently also affiliated to the Irish trade union confederation, the ICTU (see pages on Ireland) through the Northern Ireland Committee of the ICTU. In total the ICTU had 196,024 members in Northern Ireland on 31 December 2018.[6]


British unions are organised in a variety of ways. Some organise particular occupations such as teachers or radiographers, and, particularly in the finance industry, some just organise in a single company, such as Aegis, which covers the insurance and pensions group Aegon, or the NGSU for the Nationwide Building Society. However, the great majority of union members are now in large unions, formed by mergers, which have members in many sectors of the economy. Industry-based unions are now less common, with some industry specific unions, like the construction workers’ union UCATT and the broadcasting and entertainment union BECTU being absorbed by larger unions in recent years.[7]


The largest union in the UK is Unite, a union formed in May 2007 through the merger of the previously second and third largest unions, Amicus and the T&G. It had 1,200,303 members in January 2020, and they work in almost every sector of the economy, including motor manufacturing, printing, finance, road transport, and the health service. It is stronger in the private than the public sector, but it has at least 200,000 members in public services.


UNISON, the second largest union with 1,171,000 members, organises primarily in the public services, although because of privatisation it has substantial membership in private companies. The third largest union is the GMB, with 597,147 members. Like Unite it is a general union with members in several industries and in both the public and private sectors, although they are more likely to be manual workers.


These three unions account for 55% of total TUC membership and 44% of total union membership.


The next group of TUC affiliated unions by size are smaller and are more linked to specific industries and occupations. There are seven each with more than 100,000 members: the NEU teaching union (439,038 members), which was formed by a merger of two teaching unions, the NUT and the ATL in 2018; USDAW (411,435), which primarily organises shop workers but has members in other areas; another teaching union, the NASUWT (284,062);  the CWU (198,235), which covers  postal and telecommunications workers, although not management grades; PCS (177,361), which primarily organises civil servants in central government; Prospect (143,776), which organises specialists and managers, many in central government; and the UCU (112,765), whose membership is academic staff in higher education and vocational colleges.


The remaining 38 unions range in size from the RMT rail and transport union, with 85,861 members, to the miners’ union, the NUM, which was once one of the most powerful of the UK’s union but now has just 241 members. There are 14 TUC affiliates with between 85,000 and 20,000 members, 11 with few that 20,000 but more than 5,000 members and 13 with fewer than 5,000 members.


Individual unions affiliated to the TUC are independent in terms of their decision-making, although the TUC remains a key channel for discussions with government.


The 48 TUC affiliates are among 139 union operating in Britain in 2019, according to figures from the Certification Officer, the head of the government agency responsible for monitoring union compliance with legislation. The remaining 91 union are mostly very small: 56 non-TUC union have fewer than 1,000 members and another 21 have more than 1,000 but fewer than 2,500.  However, although the vast majority of non-TUC unions are small, there  two large unions, which are not affiliated to the TUC – or any other body. These are the RCN, which organises nurses and has 458,142 members, making it the fourth largest union in the country, and the BMA, which organises doctors and has 155,792.[8] Police officers, who by law are prohibited from joining a trade union or taking industrial action, are organised in different staff associations based on rank and geography. The largest is the Police Federation of England and Wales for rank-and-file police, which has around 130,000 members.[9]


Around half the membership of the TUC belongs to unions that are affiliated to the Labour Party, although the TUC itself is not affiliated. The exceptions are largely among unions representing professional staff, such as teachers, some health staff and civil servants. Affiliated unions are present and vote at Party conferences and are represented on the executive committee of the Labour Party as well as being the single largest source of Labour Party funds. However, as a result of rule changes, unions now have much less formal influence on Party policy than in the past.


Trade unions lost membership heavily during the 1980s and the first half of the 1990s, largely because of changes in the structure of the workforce. However, in the late 1990s, the sharp loss of members was halted and since that time the proportion of employees who are union members has declined more slowly. Over the 20 years from 1999, the Labour Force Survey figures show union membership among employees declining by a total of 7.7%, from 6,978,000 in 1999 to 6,440,000 in 2019, while union density on fell by 6.2% percentage points – down from 29.7% to 23.5% - over the same period. In the three years 2017 to 2019, trade union membership has increased year by year and, in 2019, it was 210,000 higher than it had been in 2016, although with increasing number of employees in the economy over this period, this meant that union density was the same in 2019 as it had been in 2016.


Since the 1990s, the TUC and individual unions have devoted greater resources to recruiting and organising new members. One example was the creation of the TUC Organising Academy in 1998, which hoped to “encourage unions to invest more heavily in organising activity and to attract new people to work in the trade union movement as organisers, policy makers and officials”. The Academy trained 400 specialist organisers, although its courses are now only offered to trade union officials.[10] Other examples include: Unite’s “100% campaign” aimed at maximising membership in workplaces where Unite already negotiates with employers and Unison’s network of local organisers,  who are employed to “recruit new members and work with regional organising teams, mapping membership density and campaigning to develop new activists”.[11]


Trade union density is much higher in the public sector (52.3% in 2019)  than in the private sector (13.3% in 2019), and, as a result, there are more public sector trade unionists (3.77 million in 2019) than private sector trade unionists (2.67 million). This is despite the fact that the private sector employs three times many as the private sector.[12]


It is the higher proportion of women working in the public sector that largely explains why a higher proportion of women are union members than men – 27.0% as opposed to 20.1% (2019 figures). This gap in union density of almost seven percentage points is present. even though in the private sector men’s union density is higher at 13.9% than women’s at 12.5%, and in the public sector there is only a relatively small difference in favour of women, with 53.9% of women and 49.0% of men being union members. The overall result is that there are almost a million more women who are trade union members than men: 3.69 million women and 2.75 million men.

[1] This is made up of 6,695,098 union members in unions with headquarters in Great Britain – Annual Report of the Certification Officer 2019-20, June 2020, plus 47,592 in unions based in Northern Ireland, and a further 11,507 in unions based in the Republic of Ireland – Annual Report of the Certification Officer for Northern Ireland 2018-19, June 2020. The figures are for the end of December 2018 for Norther Ireland and, in most cases, for the end of December 2019 for unions based in Great Britain

[2] This and all figures for union density in this section come Trade Union Membership, UK 1995-2019: Statistical Bulletin, Department for Business, Energy and Industrial Strategy, May 2020

https://www.gov.uk/government/statistics/trade-union-statistics-2019  (Accessed 08.01.2021)

[3] Transparency of Lobbying, Non-party campaigning and Trade Union Administration Act 2014

[4] Jelle Visser, ICTWSS Data base. Version 6.1. Amsterdam: Amsterdam Institute for Advanced Labour Studies AIAS. October 2019

[5] Figures for TUC and TUC affiliated unions are from TUC Directory 2021 

[6] Report of Executive Council to the Biennial Delegate Conference of the Irish Congress of Trade Unions, July 2019, https://www.ictu.ie/download/pdf/bdc_2019_report.pdf (Accessed 08.01.2021)

[7] For an analysis of the situation and development of trade unions in the UK see Dependence on a hostile state: UK trade unions before and after Brexit by Genevieve Coderre-LaPalme and Ian Greer in Rough waters: European trade unions in a time of crises, edited by Steffen Lehndorff, Heiner Dribbusch and Thorsten Schulten, ETUI, 2018

[8] Annual Report of the Certification Officer 2019-20

[9] Police Federation website https://www.polfed.org/about-us/ (Accessed 08.01.2021)

[10] 10 years on: the impact of the Organising Academy on the union movement by Jane Holgate and Melanie Simms, TUC General Council Report 2011 and TUC Organising Academy 2019 Course Programme, 2018 https://www.tuc.org.uk/resource/tuc-organising-academy-2019-course-programme (Accessed 08.01.2021) 

[11] Unite leaflet http://unitealliance.org/wp-content/uploads/2017/10/Organising-leaflet.pdf  and Unison website https://www.unison.org.uk/about/jobs/2019/08/eastern-region-local-organiser-7/ (Accessed 08.01.2021)

[12] Trade Union Membership, UK 1995-2019: Statistical Bulletin, Department for Business, Energy and Industrial Strategy, May 2020

L. Fulton (2021) National Industrial Relations, an update (2019-2021). Labour Research Department and ETUI (online publication). Online publication available at http://www.worker-participation.eu/National-Industrial-Relations.