A pressure group or interest group ( the terms are often but not always used interchangeably ) is an organised association which aims to influence the policies or actions of government. pressure groups differ from political parties in that they seek to exert influence from outside, rather than to win or exercise government power. Further, pressure groups typically have a narrow issue focus, interests of a particular group, and seldom have the broader programmic or ideological features that are generally associated with political parties. Pressure groups are distinguished from social movements both by their greater degree of formal organisation and by their methods of operation. Pressure groups that operate at the international level ( particularly in relation to development and environmental issues ) have increasingly been accorded formal recognition as non-governmental organisations (NGOs). Nevertheless, not all pressure groups have members in the formal sense; hence the preference of some commentators for the looser term 'organised interests'.
Pressure groups appear in a variety of shapes and sizes. The two most common classifications of pressure groups are between sectional and promotional groups, and between 'insider' and 'outsider' groups. Sectional groups ( sometimes called protective, functional or interest groups) exist to advance or protect the ( usually material ) interests of their members. The 'sectional' character of such groups derives from the fact that they represent a section of society: workers, employers, consumers, an ethnic or religious groups, and so on. In the USA, sectional groups are often classified as ' private interest groups' , to stress that their principal concern is the betterment and well-being of their members, not of society in general. Promotional groups (sometimes termed cause or attitude groups) are set up to advance shared values, ideals and principles. In the USA, promotional groups are dubbed 'public interest groups' , to emphasise that thery promote collective, rather than selective benefits; they aim to help groups other than their own members. Nevertheless, many pressure groups straddle the sectional / ptomotional divide, in that they both represent their member' interests and are concerned with ideals and broader causes. Trade unions, for instance, often address the issue of social justice as well as matters such as wages, conditions and job security.
Alternatively, pressure groups can be classified on the basis of theri relationship to government. Insider groups enjoy privileged and usually institutionalised access to government through routine consultation and representation on government bodies. Such groups either tend to represent key economic interests or to possess specialist knowledge and information necessary to government in the process of policy formulation. Outsider groups, on the other hand, are either not consulted by government or consulted only irregularly, and not usually at a senior level. Lacking formal access to government, these groups are forced to 'go public' in the hope of exercising indirect influence on the policy process via media and public campaigns.