Wikipedia
NASUWT
The National Association of Schoolmasters Union of Women Teachers (NASUWT) is a TUC-affiliated trade union representing teachers, including headteachers, throughout the United Kingdom.
The union organises in all sectors from early years to further education and represents teachers in all roles including heads and deputies. With over 300,000 members it's the second largest teachers' union in United Kingdom. The NASUWT claims to be independent of any political party, and seeks to influence educational policy on behalf of its members with national government and the devolved assemblies in Scotland, Wales and Northern Ireland.