Proportional representation "is an absolute bottom line for us," in any debate over a possible coalition. So says the former Liberal Democrat leader, Charles Kennedy.
Interviewed by Today presenter John Humphrys, Mr Kennedy said that the prospect of a governing party going from first to third in the polls and remaining in power was "a constitutional outrage" and "an offence against common sense".
But the former Conservative Party leader Iain Duncan Smith told the programme that the public was not keen on a hung parliament, adding he did not believe that his party "wants, or believes it's necessary, to have electoral reform," adding "I don't think that sort of deal is in the air".
His comments come as Tory election strategists prepare to target constituencies where they say Labour support is ebbing away.
The Business Secretary Lord Mandelson has insisted the contest is still wide open and the Liberal Democrats' leader Nick Clegg, who is campaigning in Scotland today, has claimed it is a straight fight there between the Liberal Democrats and Labour.
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