In addition to lobbying, campaigning, debating and carrying out other representative activities, most students' unions facilitate 'student activities' (societies, volunteering opportunities, and sport) peer-led support (through advice centres, helplines, job shops and more), and social venues to bring their members together.
Most unions receive some funding through an annual allocation, also called the block grant, from their educational institution.
The then Education Secretary, John Patten aimed to end the 'closed shop' and ensure students would have to join their union (opt-in) rather than automatically becoming a member.
As many unions receive funding based upon membership levels this threatened their ability to achieve their core business.
The Act states that if a petition signed by a minimum number of students (the threshold cannot exceed 5 per cent) is lodged then a referendum must be held on whether or not to end one of the union's affiliations.
Money donated to a students' union is subject to ultra vires law and can only be spent to further this charitable purpose.
Where separate students' unions still exist (for example at the University of Glasgow), they operate as private members' clubs.
In Northern Ireland, students' unions operate in a similar way to those in Great Britain, except that they cannot exclusively be members of NUS.