The UK's voluntary sector is huge, employing around 500,000 people, and growing faster than many industries. Charities range from tiny self-help groups through to multi-million pound organisations employing 100s of staff. They have a wide range of concerns ranging from social deprivation, politics and children to animals, cultural heritage and medical research, both in the UK and overseas.

Helping in crises

British charities work in crisis areas around the world, including most recently in Burma, Sudan and Bangladesh. Some well-known UK based charities include:

• Oxfam
• Amnesty International 
• Christian Aid
• Save the Children

The Charity Commission regulates charities and voluntary organisations in England and Wales. You can also search a database of charities on its website.

You can find information about Scottish charities and non-government organisations (NGOs) on the Office of the Scottish Charity Regulator website.

The NI Council for Vountary Action provides details about voluntary organisations in Northern Ireland.

British think tanks

Think tanks conduct research into areas such as social policy, the economy and political strategy, with the aim of shaping government policy. Although some think tanks are politically impartial, many are affiliated to political parties, which often leaves them open to accusations of bias.

Famous UK think tanks include Chatham House, which focuses on foreign policy; the Adam Smith Institute, which concentrates on economic matters; Civitas, on the relationship between government and civil society; and the centre-left Institute for Public Policy Research, which is associated with new Labour ideas.

You can find profiles of Britain's leading think tanks on the Guardian Unlimited website.