Liberal Democrat leader Nick Clegg, whose party is still riding high in the polls, says that electoral reform could be a deal breaker for a post-election hung parliament arrangement.
Along with a substantial minority in the Labour Party, the Greens, the SNP, Plaid Cymru and other small parties, the Lib Dems argue that proportional representation is key to a fairly elected democratic assembly.
Mr Clegg says that whoever formed the next government will now have to accept that reform of the electoral system is inevitable, and that any Tory opposition to such reform would be a "massive strategic error", reports the BBC.
Changing the unfair first-past-the-post system, which enshrines a two party monopoly in Britain, even though millions of voters are choosing other parties or independents, is something political reformers right across the spectrum say is essential - and it is an important part of what those who want to see a hung parliament are lobbying for (http://hang-em.com/).
Mr Clegg's comments came in an interview with the popular broadcaster and Channel 4 'Big Brother' reality show presenter, Dermot O'Leary, to be screened on BBC3 on Wednesday 28 April 2010.
The BBC has been 'trailing' excerpts of the Liberal Democrat leader's comments on its radio news and website this morning, and national newspapers have been interpreting what he has said, or is anticipated as saying, in very different ways.
In the BBC3 interview, Mr Clegg will speak for the first time about the possibility of sitting in cabinet with rival parties after the general election.
"When the electorate make up their mind, we've got to accept the verdict," he says, adding that he believes it would be "arrogant" to make assumptions about the situation after the election.
Proponents of political reform say that the capacity of the Liberal Democrats and others to push for PR and similar changes under a 'hung' or balanced parliament where no one party has an absolute majority, should not be confused with endorsing an specific party.
However, many people are committed through online campaigns to vote tactically to increase the possibility of a hung parliament, which the polls are still showing as a likely outcome.