Fresh tensions at the top of the coalition erupted last night last night as a senior Liberal Democrat branded their Conservative coalition partners "Neanderthals" who had not "arrived in the 21st century".
In an exclusive interview with The Independent on Sunday, Lib Dem deputy leader Simon Hughes served notice that his party would pull no punches in campaigning for a positive outcome in next year's referendum on the Alternative Vote system.
"I think it is an entirely winnable campaign but only if we are really clear that people defending first past the post are Neanderthal," he said. "Now, they may be our colleagues in government, but it's an indefensible, unfair, illogical minority activity to defend first-past-the-post. We have got to go in really hard ... If you can't support the idea that preferential voting and getting a majority of support in your area is progress, then really you haven't arrived in the 21st century."
David Cameron has repeatedly argued in favour of retaining first-past-the-post, claiming it enables voters to "kick out" a Government. When Labour proposed a move to AV, he branded it a "fix". Under AV, voters rank candidates in order of preference, and later preference votes of losers are redistributed until the winner has the support of more than 50 per cent.
The Tory MP George Eustice, who is co-ordinating the No to AV campaign, said: "Our one-person, one-vote system ... gives us clear and strong government. The only countries that have an AV system along the same lines being proposed are Fiji and Papua New Guinea. It is clearly ridiculous to say that going to AV is a step forward."