http://www.legislation.gov.uk/ is the official site for UK legislation as its originally made (as enacted) and with the latest version, which shows how the legislation has changed. Please look on this website if you cannot find a relevant link below.
http://www.official-documents.gov.uk/ is the official reference facility for Command and departmentally sponsored House of Commons Papers. All Command and House of Commons papers published from May 2005 onwards, as well as key Departmental papers, are available for free on the site in PDF format.
Overton is the world’s largest collection of policy documents, parliamentary transcripts, government guidance and think tank research.
You will need to select the OpenAthens login option to gain access.