Legislation - whether it be in the form of act of Parliament or statutory instrument - has, since the late (20th, become the dominant source of English labour law.
Holders of an Oxford SSO must always use a subscription database to be sure of finding the current (amended/consolidated) text of UK legislation.
Printed resources
Halsbury's Statutes and Statutory Instruments and Current Law Statutes Annotated are in the KZ section on Level 2.
These are the services which enable you to get as close as possible to the current state of active legislation, tracking subsequent amendments etc.
Cw UK 001-099 Level 1
Here you will find the texts of statutes & statutory instruments as originally promulgated, and various indexes and chronological tables.
This is not the Law Bod's entire collection of acts - please ask a member of staff for assistance if you cannot find the particular piece of legislation you require.
For help in finding the legislation of non UK jurisdictions please see if we have a separate guide which can give assistance