There is a widespread perception that public sector offers an employment advantage for groups disadvantaged generally in the labour market. For example women are more than twice as likely to work in the public sector as men. The relative concentration of these protected groups within the public sector has increased over the past decade of public sector employment growth and also as employment has contracted during the early years of the recession from 2008. The public sector also offers pay premia to its employees relative to the private sector and this is reflected in lower pay gaps for disadvantaged groups (Elliott et al 1996; Perfect 2011).

Explanations for public sector advantage include the status of government as a model employer which recognises its employees as stakeholders (Beaumont 1981), a set of cultural values (Woodhams and Corby 2007) and positive employer attitudes (Kumar 1993) which have promoted the proactive recruitment of minority groups, more sophisticated and advanced equality and diversity management (Bender and Elliott 1999; Cai and Lui 2011; CIPD 2007), including greater adoption of substantive equal opportunities policies (Hoque and Noon 2004). Stricter regulatory controls apply in the public sector, for example the Single Status Agreement 1997, the NHS Agenda for change 2004 and, since 2011, additional demands contained within the Public Sector Equality Duty. A recent literature points to a positive association between unionization and workplace equality practices (Blanchflower and Bryson, 2010) and Hoque and Bacon (2012) propose an interaction between regulation and unionization where the stricter regulatory structure might provide public sector unions with additional leverage in negotiations over equality issues.