Labour will fight the general election by promising to change the voting system as part of a decade-long programme to build a "new politics".
Gordon Brown yesterday set out plans for wide-ranging constitutional reform which he claimed would restore the shattered trust between politicians and the public following the expenses scandal.
They include removing hereditary peers from the House of Lords, giving voters the power to remove corrupt MPs and drawing up Britain's first written constitution.
He is to force a Commons vote next week on holding a referendum on scrapping the first-past-the-post election system for MPs.
Under the Prime Minister's plans, a nationwide poll would be staged by October next year on replacing first-past-the-post with the alternative vote, under which electors place candidates in order of preference.
His move to win Commons approval before the election for the referendum looks doomed to fail because of Tory resistance and lack of parliamentary time. The plan would then feature prominently in the Labour election manifesto.
Mr Brown said he would campaign personally in a referendum for a switch to AV, arguing it would make MPs more representative and accountable.
He said: "It means each elected MP will have the chance to be elected with much broader support from their constituency, not just those who picked them as their first choice."
The attempt to change the voting system will be seen as a move to woo Liberal Democrats in the event of a hung parliament, as well as an effort to appeal to their natural supporters.
The Lib Dems last night mocked the Prime Minister's "deathbed conversion" to electoral reform, while the Conservatives made clear they would oppose attempts to rush the referendum plans through Parliament. Eric Pickles, their party chairman, accused him of being prepared to "say anything to cling to power".
Mr Brown, who has acknowledged the public had been "rightly outraged" by the expenses crisis, has confirmed plans to give voters the authority to "recall" dishonest MPs by forcing them to face a by-election.
The power would be triggered "in grave situations where financial impropriety has been proven, but where Parliament itself has failed to act".
Mr Brown has told MPs he favoured lowering the voting age to 16, but said it could only be done in conjunction with wider reforms, including better citizenship education in schools and a formal citizenship ceremony at 16.
Reform: Main points
* Holding a referendum on replacing the first-past-the post system with the alternative vote. If approved, it would be an historic change.
* Finally delivering on Labour's century-old commitment to removing hereditary peers from the Lords.
* Codifying all the unwritten rules on government into a single document.
* Producing a written constitution by 2015, the Magna Carta's 800th anniversary.
* Giving voters the power to expel crooked MPs.
* Allowing petitions with enough public support to be debated in the Commons.
* Ceding more control to MPs over Commons business and who chairs its select committees.
* Releasing documents more quickly.Reuse content