Salisbury Convention: A Decade of Developments

The Salisbury Convention is commonly understood to mean the House of Lords gives a second reading to government bills that seek to implement manifesto commitments, does not subject them to wrecking amendments and returns them to the Commons in reasonable time. It is also sometimes called the Salisbury-Addison Convention.

The convention arose from an understanding between the leaders of the Labour and Conservative parties in the House of Lords after the 1945 general election. At that time, Labour had a majority in the House of Commons but the Conservatives had a majority in the Lords. The modern expression of the convention was set out by the Joint Committee on Conventions in 2006.

The Salisbury Convention relates to a government’s manifesto bills. This is based on the idea that manifesto bills have a special form of democratic legitimacy as they have been voted for by the electorate. There is a recognition that it is not always straightforward to identify which bills should be classed as manifesto bills, especially as modern manifestos tend to be more complex than in 1945 when the convention originated. However, it has also been pointed out that in practice the Lords does not usually block any government bill, regardless of whether it is a manifesto bill.

The 2010 and 2017 general elections both produced hung parliaments. This gave rise to questions about whether the Salisbury Convention applies to a coalition or minority government.

In 2017, the minority Conservative Government argued the Salisbury Convention should apply to its manifesto pledges. Other parties in the Lords were not convinced of this argument but acknowledged the Lords would be mindful of the balance of power between the two Houses. During the 2017–19 parliament, Brexit supporters claimed that Lords amendments to the European Union (Withdrawal) Bill and the Data Protection Bill were ‘wrecking amendments’ that violated the Salisbury Convention. Others argued that in making these amendments, the Lords was fulfilling its constitutional role by asking the Commons to think again.

In 2010, the Conservative-Liberal Democrat coalition government initially asserted the convention still applied, although others across the House felt it was not so clear-cut. In 2011, the Government acknowledged the convention did not operate in the same way with the advent of a coalition government. Two parliamentary committees both concluded that a coalition agreement made after an election had produced a hung parliament did not have the same status as a manifesto. During the period of the Coalition Government, there were attempts to block three government bills at second reading in the Lords, all of which failed.

• House of Lords Library, 'The evolution of the Salisbury convention', 21 November 2022