British Prime Minister David Cameron will today share a platform with the Labour former Cabinet heavyweight John Reid as the battle over electoral reform escalates and cuts across party lines.
At the same time, Liberal Democrat Cabinet minister Vince Cable will be sitting alongside Labour leader Ed Miliband to make the case for changing the voting system.
With 17 days to go to the referendum on voting in Britain, politicians are to intensify hostilities in a contest that is too close to call.
Tensions within the Coalition have been exacerbated by the referendum campaign. The differences were underscored yesterday by rival television interviews by the Prime Minister and his deputy.
Cameron claimed that first-past-the-post was straightforward and popular around the world, and Nick Clegg countered that the alternative vote was fairer and more democratic.
The Prime Minister also echoed Chancellor of the Exchequer George Osborne's allegation that the commercial arm of the Electoral Reform Society, the biggest financial backer of the Yes campaign, stood to profit from a switch to AV. Electoral Reform Services Ltd denies any conflict of interest.
The repeated assertion has infuriated the Yes camp. Cameron will be joined by Lord John Reid as he steps up his attack on AV. He was to claim that the vote on May 5 is crucial to "the future of our democracy".
He will say: "The biggest danger right now is that Britain sleepwalks into this second-rate system, waking up on May 6 with a voting system that damages our democracy permanently. We must not let that happen."
Reid will argue that first-past-the-post has been the "foundation of our democracy for generations". He will say: "There are some issues so important that they transcend party politics, issues on which people expect politicians to put aside their party differences for the sake of the people and the public interest."
Cable will defy his Tory critics by taking to the stage with Miliband to make the case for electoral reform. The Business Secretary has ruffled feathers within the Coalition with his attack on Cameron's "very unwise" speech last week on immigration.
Today he will find common cause with the Labour leader to argue that a system under which an MP requires 50 per cent support to be elected will strengthen links with voters.
Clegg told BBC 1 yesterday: "After the expenses scandals, people want some change. They want the system cleaned up. They want a system which I think would be delivered by AV which is fairer, which makes MPs work harder for your vote, which makes every vote count. It's actually a relatively modest change to the current system."