UP TO five constituencies in the Merseyside area will change hands if voters back the “alternative vote” (AV) system in today’s referendum, an expert has predicted.

The analysis, by the professor of politics at the University of Liverpool, appeared to scotch claims that the result will have little impact on general election results.

However, it also found that the Liberal Democrats – the main supporters of a switch to AV – would fail to gain any extra seats in the area.

The analysis was revealed as the Cabinet war over AV plunged to new levels of acrimony this week, with David Cameron confronted over misleading “No” leaflets, across the Cabinet table.

Chris Huhne, the Lib-Dem Energy Secretary, was reported to have waved the controversial leaflets around, while challenging the Prime Minister about their tendentious claims.

In an interview, the Prime Minister ducked an invitation to condemn posters claiming babies will die and soldiers’ lives put at risk because of the alleged higher cost of AV.

A poll, for The Independent, gave the “No” camp a crushing 32-point lead among people who are absolutely certain to vote today, suggesting that opposition to a switch is hardening.

Under AV, voters rank candidates and second preferences are transferred from last-placed candidates who are knocked out, until one achieves 50% of the vote.

Supporters argue there will be fewer safe seats, forcing MPs to work harder and reach out to more voters – but first-past-the-post backers warn of more coalitions, with government decided by horse-trading and “political fixes”.