The BBC is not responsible for the content of external internet sites
POLITICAL PARTIES IN COMMONS
These parties have one or more MPs in the House of Commons:
PARTIES WITH MEMBERS IN SCOTTISH PARLIAMENT, WELSH ASSEMBLY, LONDON ASSEMBLY OR EUROPEAN PARLIAMENT
POLITICAL PARTIES REGISTERED BY ELECTORAL COMMISSION
GOVERNMENT AND MINISTRIES
OTHER POLITICAL WEBSITES
There are far too many political blogs to list in full, but Alan Connor, from the BBC's Daily Politics programme, has written a guide to them which includes links to many of the best known.