A referendum on changing the way MPs are elected will be held by October next year under Government plans passed by the Commons tonight.
Despite strong opposition from the Tories and vocal criticism from some Labour backbenchers MPs voted 365 to 187, Government majority 178 to ask the British people to decide whether the traditional first-past-the-post system should be scrapped in the biggest shake up of the election system in generations.
But the Government faces an uphill battle to force the changes through Parliament with the prospect of stiff resistance in the House of Lords and time running out before the general election.
Gordon Brown's proposal would allow people to choose whether to adopt an Alternative Vote (AV) system which would allow them to rank candidates in order of preference.
Critics accused Mr Brown of a cynical ploy in order to win the support of Liberal Democrat MPs in the event of a hung parliament at the next general election.
The Government also came under fire over the £80 million cost of the plebiscite at a time when public spending is under intense pressure due to the record budget deficit.
The proposals came in committee stage amendments to the Constitutional Reform and Governance Bill tabled by Justice Secretary Jack Straw.
He told MPs the expenses scandal had led to a "crisis of confidence in our political system and in our politicians on a scale which none of us have witnessed in our political lifetime".
He added: "This is an important debate. This subject is a fundamental plank of our democracy and it comes at a time when this House is held in dangerously low regard.
"The alternative vote takes on the considerable strengths of our system and I suggest builds on it.
"We propose a referendum because we believe it is not for us to decide, but it is important the people should have that choice."
Labour former minister Tom Harris (Glasgow S) raised laughter as he asked Mr Straw: "Do you attribute the stainless reputation of Italian politicians to the fact that they have proportional representation?"
Mr Straw said the AV system was not proportional representation.
Lynne Jones (Lab, Birmingham Selly Oak) asked why the recommendations of the Royal Commission set up by the Government were not being put forward to prevent the issue being "tainted" by party politics.
Mr Straw told her the Jenkins commission report in 1999 had established "no consensus" around reform.
Labour former minister Frank Field (Birkenhead) said AV was "illogical" and spoke in favour of the French system where the top two candidates take part in a run-off if neither achieves 50% support in the initial ballot.
He suggested the Government's proposals would face strong opposition in the Lords when the Bill is debated by peers.
Shadow justice secretary Dominic Grieve said he felt "truly sorry" for Mr Straw for having to present the Prime Minister's plans to Parliament.
"The Secretary of State was fighting, I think, a rearguard action against the Prime Minister, who was both losing the plot and was taking leave of his political sense in a desperate bid to stay in office," he said.
He expressed his backing for first-past-the post, saying it "delivers clear, clean results".
Former Cabinet minister John Gummer (C, Suffolk Coastal) said it was a "scandal" MPs were being asked to approve around £80 million to pay for the referendum at a time when all parties were discussing cuts to deal with the state of Britain's finances.
He accused Mr Brown of putting "his own future before that of this nation".
Douglas Hogg (Sleaford and North Hykeham), another Tory former Cabinet minister, dismissed it as "an act of pure political cynicism".
Liberal Democrat spokesman David Howarth said Mr Brown had undergone a "deathbed conversion" on the issue of electoral reform.
The Liberal Democrats wanted to see the more radical single-transferable vote (STV) as a referendum option but said AV was "a small gain but a gain worth having".