Salisbury Convention

The Salisbury Convention (officially called the Salisbury Doctrine, the Salisbury-Addison Convention or the Salisbury/Addison Convention) is a constitutional convention in the United Kingdom under which the House of Lords should not oppose the second or third reading of any government legislation promised in its election manifesto. The origins of the convention date back to the late 19th century, at which time the Conservatives held a majority in the House of Lords and, with the support of the third Marquess of Salisbury, developed the "Referendal Theory", which applied solely to Liberal legislation, under which the House of Lords could obstruct legislation until it had received majority approval at a general election.^[1] This was changed following the landslide Labour Party victory in the 1945 general election, which produced a Labour government seen as having a popular mandate for significant reform, while once again there was a Conservative majority in the House of Lords. The fifth Marquess of Salisbury (grandson of the third) announced that the Lords "would not seek to thwart the main lines of Labour's legislation provided it derived from the party's manifesto for the previous election". From this point, manifesto bills were only to be adjusted by the Lords; however, on non-manifesto bills, the Lords were able to act as they had before.