Voting reform campaigners have privately declared the Liberal Democrats "toxic", fearing Nick Clegg's plummeting popularity in the polls will choke off their hopes of winning this year's referendum on a new voting system.
Strategists behind the push to adopt the alternative vote on 5 May are positioning the campaign as the people vs the politicians, capitalising on the anti-establishment mood that began with the expenses scandal and has gained new energy since a series of U-turns by Mr Clegg's party.
However, The Independent on Sunday has learned that the Labour leader, Ed Miliband, will make a public offer to share a platform with Mr Clegg to campaign for a Yes vote. Sources close to Mr Miliband say he will campaign "vigorously" to replace the current first past the post (FPTP) system, despite some analysis suggesting it could disadvantage Labour in the polls.
Labour supported AV in its general election manifesto "to ensure that every MP is supported by the majority of their constituents voting at each election". However, more than 100 Labour MPs have since signed up to the No campaign. A Labour source said: "Those opposing reform are from the old generation, rather than what some have called Generation Ed. Ed is prepared to work with Nick Clegg in the interest of something he believes in. This is what we mean when we talk about new politics."
Under AV, instead of crossing a box to vote for one candidate to become their MP, voters rank the candidates in order of preference. After the first count, if no one has secured 50 per cent of first preferences, the candidate with the fewest votes is eliminated and their second preferences are redistributed. The process is repeated until someone has secured the support of more than half of those who voted. In the 2010 election, two-thirds of MPs failed to secure 50 per cent of the vote.
A report by the Institute for Public Policy Research last week denounced FPTP as "broken" and suggested long-term changes in voting patterns mean hung parliaments and coalitions will become a more familiar fixture in British politics. More than a third of votes in the 2010 general election were cast for parties other than the Labour or the Tories.
The staging of a referendum on electoral reform was key to the Lib Dems agreeing to form a coalition with the Conservative, despite the Tories' fierce opposition to change.
However, since then the Lib Dems have seen their popularity plunge from 24 per cent on polling day to 7 per cent in an opinion poll last week. A source close to the Yes campaign said: "The Lib Dem brand is now toxic, like most political parties, and we need to make this about the people taking back control." Mr Clegg has conceded his profile is no longer an asset to the pro-reform movement, insisting last month: "I don't think the Yes campaign should be run by politicians at all. This is all about the case for giving people more say over politicians."
According to an ICM poll commissioned by the Yes campaign, of those intending to vote, 58 per cent backed AV with 42 per cent against. In Scotland, where national elections on 5 May will boost turnout, support was 62 per cent.
Paul Sinclair from the Yes to Fairer Votes Campaign said: "This isn't about Nick Clegg or any one politician. It is about renewing our democracy. It is about improving our system so it better reflects the views of the people. It is about giving the people, for the first time in history, the right to decide how we elect our politicians."
The Yes campaign has positioned itself as a grass-roots movement, with dozens of local leaders planning up to 50 phone banks in 40 towns. More than 150,000 names have been added to mailing lists, with a website already set up to receive donations.
A number of high-profile celebrity backers are expected to go public in the next four months. The comedian Eddie Izzard has already put his name to a fundraising drive, urging supporters to donate money to "put a nail in the coffin of first past the post". He said: "It's time for change. It's time for an upgrade to help fix the problem."
In contrast to the Yes campaign's attempt to distance itself from the political elite, the No campaign has recruited veteran Labour and Tory figures including Lord Prescott, Lord Reid, David Blunkett and Lord Falconer and senior Tories such as the Foreign Secretary, William Hague, and Justice Secretary, Ken Clarke.
The No to AV campaign produced six million leaflets and launches a new website tomorrow. It focuses on Mr Clegg's claim before the general election that AV is a "miserable little compromise" and Chris Huhne suggesting: "The alternative vote does not give voters real power."
A major criticism of AV will be that it is used for elections only in Australia, Fiji and Papua New Guinea, though it is used to choose the Labour Party's leader and in elections for posts in the House of Commons.
Matthew Elliott, campaign director of No to AV, said: "People see the country as a two-party system, where Labour gets its turn and then the Tories get their turn. The Lib Dem stance of either sitting on the fence or saying different things in different places has been exposed by in government." He added that it was "dishonest" that many of the people now arguing in favour of AV had previously condemned it.
Joan Ryan, the No campaign's deputy director and a former Labour minister, said AV would lead to more coalitions, something voters may resist after seeing the decisions taken by the Government. "At an election you give an absolute commitment, but the trouble with the coalition is it gives an absolute excuse to break your promises," she said. "That's very damaging to our electoral system."
"We should have a more proportionally representative system, as first past the post hasn't served us particularly well. Alternative vote isn't ideal but it would be a mild change for the better."
Naomi Alderman, Author
"I think the alternative vote system should be used. It will give a fairer result and the whole system needs a shake-up."
Melvyn Bragg, Author and broadcaster
"I want to know if the electorate are aware about how much the alternative vote could change politics. Smaller parties would play a bigger role and for democracy that's a good thing."
Bonnie Greer, Playwright and critic
"The first past the post system is completely undemocratic. I'd like to see the recommendations of the Jenkins report which proposes the AV+ system, a hybrid of different voting methods."
Dick Taverne, Liberal Democrat peer
"The alternative vote system is a step in the right direction towards real democracy. We don't have to vote tactically to keep people out, but can vote for our first-choice candidate without fearing our vote will be wasted."
Francesca Martinez, Comedian
"I'm a great fan of the first past the post system, and it's amusing that the Liberal Democrats are asking for change at a moment when they have more power than they could have dreamed of."
Esther Rantzen, Television presenter
"The latest election showed people are terrified by the vagueness of their views. First past the post is faster and more dramatic, which suits the British psyche – then again, you do like Test matches."
Dara O'Briain, Comedian and presenter
"The whole referendum is a smokescreen. Although it's the right direction towards democracy, anything but proportional representation is a distraction from the real issue."
Paul Heaton, Singer-songwriter
"There are politically stable and chaotic countries that have similar systems to the alternative vote. It's swings and roundabouts, but I won't be voting in a referendum."
Alexei Sayle, Comedian
"The public might have been interested in proportional representation before because they felt the Lib Dems were being treated unfairly. The desire for voting reform has waned. Personally, I don't care."
Mark Steel, 'Independent' columnist