An updated edition of Parliament's guide to practice and procedure has been launched to reflect changes in the way the House of Commons and the House of Lords operate.
Erskine May: Parliamentary Practice, often referred to as Parliament's bible, is now in its 24th edition and is used throughout the Commonwealth.
It provides accurate and detailed information on Parliament, its powers and jurisdictions, its membership, financial procedure and the process of debates.
In the latest edition, a number of changes have been made to cover developments in the constitution, Parliamentary privilege, and Parliamentary procedure.
These new additions cover areas such as the impact of a Coalition Government, the respective roles of Parliament and the courts, the creation of the Supreme Court, the election of select committee Chairs and the establishment of a Backbench Business Committee.
It was originally written by British constitutional theorist Thomas Erskine May in 1844 when he was aged 29. He went on to become Clerk of the House of Commons and spent 55 years advising members on constitutional and procedural subjects.
Editor and Clerk of the House of Commons Sir Malcolm Jack said: "When the first edition came out in 1844 it was instantly recognised as a work of huge significance.
"It is the product of many minds over many generations but we endeavoured to present an updated and modern version of May which I hope meets the requirements of the next few years."
Thanking Sir Malcolm for his contribution, Deputy Speaker Nigel Evans said: "He has left us a little treasure which will guide our procedures for the future."