On 18 January 2011, committee stage of the Parliamentary Voting System and Constituencies Bill continued in the Lords, following an all-night sitting in the chamber.
Peers considered a series of Labour amendments to the bill over the course of a 21-hour debate,
amid speculation that the legislation would not become law in time
for the electoral reform referendum to take place on 5 May.
Under the coalitions plans, the public will be asked to decide whether to adopt the alternative vote (AV) system - whereby voters rank candidates in order of preference - or stick with first-past-the-post.
Labour has threatened to derail ministers' plans to hold the referendum on the specified date unless more time was allowed to consider plans to cut the number of MPs from 650 to 600.
Labour opposes plans for a smaller House of Commons and objects to the measures being grouped in the same bill as the referendum.
Watch the first part of the debate
Watch the second part of the debate
Watch the third part of the debate
Watch the fourth part of the debate