result of the new legislation, the sixth general review of parliamentary boundaries commenced. The four national boundary commissions agreed on the apportionment of seats. They had a statutory duty to produce a final report on the review by 1 October 2018, but it was not submitted for approval and never implemented at all in 2019, with Parliament and the commissions keeping the 650 seats and the boundaries as drawn before 2010. For the next election, scheduled for 2024, the newly redrawn constituency boundaries and recommendations, whose process began in January 2021, are expected to be reported no later than June 2023. Number of MPs since 1654 The numbering of Parliaments in the table below related to the Protectorate Parliaments (1654–59), the Parliaments of Great Britain (1707–1800) and the Parliaments of the United Kingdom (from 1801). Notes [a] Change came into effect during a Parliament. List of constituencies disenfranchised for corruption and re-allocated seats 1821–85 The normal number of members of parliament in this period was 658. Changes took effect on the dissolution of the previous Parliament, unless otherwise indicated. Notes [a] This change took effect during the Parliament. [b] This change took effect at the same time as the redistribution provided for by the Reform Act 1867, so the total membership of the 20th Parliament remained unchanged from the 658 at the dissolution of the 19th Parliament. [c] This change took effect during the Parliament. The Macclesfield borough constituency which was disenfranchised on 25 June 1885, should not be confused with the Macclesfield county constituency which was created under the redistribution that took effect at the 1885 United Kingdom general election and held its first election in November or December 1885. Number of MPs by country Under the Commonwealth of England, Scotland and Ireland, the Protectorate regime was established by the Instrument of Government which included a redistribution of parliamentary seats in England and Wales. It also authorised the Lord Protector and Council of State to provide for the parliamentary representation of Scotland and Ireland. This arrangement only lasted for a few years and the three components of the Commonwealth reverted to having individual parliaments. The total number of MPs representing constituencies in different parts of the United Kingdom has been varied by Act of Parliament several times since the Acts of Union 1707. In the tables below the occasions on which the number has been changed, and the number