The Competition and Markets Authority (CMA) works 'to promote competition for the benefit of consumers, both within and outside the UK. Our aim is to make markets work well for consumers, businesses and the economy.' (Quotation taken from the CMA website).
The CMA acquired its powers on 1 April 2014 when it took over many of the functions of the Competition Commission (CC) and the Office of Fair Trading (OFT).
The Office of Fair Trading was responsible for protecting consumer interests throughout the UK. It closed on 1 April 2014, with its responsibilities passing to a number of different organisations including the Competition and Markets Authority (CMA) and the Financial Conduct Authority.
In addition there are various industry regulators, the links for some of the major ones are below.
The UK Competition Appeal Tribunal (CAT) "is a specialist judicial body with cross-disciplinary expertise in law, economics, business and accountancy whose function is to hear and decide cases involving competition or economic regulatory issues." (Description from CAT's homepage.)
Neutral citation is [yyyy] CAT #
In September 2010, the LawBod became the new home of the Bodleian's Official Papers Collection.(It was formerly in the Radcliffe Camera.) Useful if you need to find out government policy statements - but they also collect publications of the OFT.
The holdings are searchable via SOLO. There are specialist librarians for this collection: please email queries to email@example.com