The House of Commons changes its size every few years. Currently there are 646 seats, which will rise to 650 at the coming General Election. David Cameron has proposed reducing the size to 585. The twentieth century began with 670 MPs , rising to a high of 707 in 1918, with 615 from 1922 to 1945. 1945 saw 640 elected; from 1950 to 1955 there were 625. There were 630 between 1955 and 1974; 635 until 1983; 650 between 1983 and 1992. 651 were elected in 1992 - and after another major change in boundaries, 659 from 1977 t0 2005.The number of Peers eligible to sit in the House of Lords changes frequently. There are no set limits - and the numbers rise with new appointments, and fall upon the death of any member. [Only Bishops 'retire' from the House of Lords - for others death is the only release].
The Senate's size is governed by Art 1 Section 3 Clause 1 "The Senate of the United States shall be composed of two Senators from each State".
The House of Representatives is fixed by statute at 435 (Public Law 62-5 of 1911) members. This number could be changed by statute. CQ Politics reported this week that a retired health care consultant in Southern California, Scott Scharpen, has filed a lawsuit in a federal district court in Mississippi contending that the law limiting House membership to 435 is unconstitutional because it violates the principle of one person, one vote.
