The Parliament Act 1911 had a profound effect on Parliament and politics in the 20th century. It followed the constitutional crisis which had begun in November 1909 when the Conservative-dominated House of Lords rejected the Liberal Government's ‘People's Budget'. In the two general elections that had followed in 1910 the issue of the House of Lords had dominated debate. The Parliament Bill sought to remove the power of the House of Lords to reject money bills, and to replace the Lords' veto over other public bills with the power of delay. In addition, it was proposed to reduce the maximum duration of a Parliament from seven years to five. The Parliament Act was passed by the House of Lords by a 131-114 vote in August 1911.

The Parliament Act 1911 did nothing to alter the Conservative-dominated composition of the Upper House, but pointed the way towards future reform by hinting that attention would turn shortly to the question of restructuring. However, the pressure of other issues, followed by the upheaval of the First World War, meant that it would be some years before the matter was looked at again.