OPINION in north London is sharply divided over whether the country should change the way we elect our MPs.

The Prime Minister this week stepped up his campaign for keeping the existing first past the post (FPTP) system as he shared a cross-party platform with former Labour home secretary John Reid.

Meanwhile, Labour leader Ed Miliband joined Liberal Democrat business secretary Vince Cable to press the case for changing to the alternative vote (AV) system.

Voters will have a chance to say whether or not they would like to see the AV system introduced in a referendum on May 5. The decision to hold a referendum was part of the coalition deal, pushed for by the Lib Dems.

In north London, opinion is blurred across party lines. On the one hand, there are those who cite last year’s election result in Hampstead and Kilburn as a clear example of how first-past-the-post is flawed.

Labour MP Glenda Jackson sneaked back into the House of Commons with a majority of 42 votes and only 32.8 per cent of her constituents’ vote.

Supporters of the Yes! campaign argue that AV is fairer because voters rank some (or all) of the candidates on the ballot paper in order of preference – so they have more choice.

An MP can only be elected once they have secured 50 per cent of the vote. If this is not achieved in the first round, the last-placed candidate is eliminated and his or her second preference votes are allocated to the survivors. This process is repeated until there is a winner.

Proponents of AV argue this will make it harder for MPs to have “safe seats”, or a “job for life” – and that they will have to work harder to get elected.

Conservative Swiss Cottage councillor Andrew Marshall supports AV.

He said: “When you have a situation, such as in Hampstead and Kilburn, where more than two thirds of those voting voted against the candidate, yet that person becomes the MP, it demonstrates the weakness of first-past-the-post.

“If you give people a second and third preference, you’d end up with an MP with 50 per cent of the vote. A lot of people would like to have a second preference vote – which is at the heart of AV.”

Keith Moffitt was re-elected leader of Camden’s Liberal Democrats, the main opposition group on the council, on Monday night.

He said: “I’m very pro AV. In a constituency like Hampstead and Kilburn, a lot of the argument at the last election was about who would win.

“With AV, you don’t have to guess because you can give your second or third preferences, so the election campaign can focus on the real issues and voters can find out what candidates really think.”

But Chris Philp, the Conservative parliamentary candidate for Hampstead and Kilburn, who came second to Ms Jackson, is vehemently opposed to AV because of the likelihood it will produce coalition governments.

There is also a high chance that a candidate who originally topped the vote can fall to second or third place in the final calculations. Supporters of the No campaign say this makes it less democratic than FPTP.

Mr Philp said: “AV will lead to hung parliaments so that the government will get chosen by Nick Clegg, not the voters.

“It also means a BNP voter’s sixth preference could end up trumping a Lib Dem, Labour or Conservative voter’s first preference.

“The current system is a one-person one vote: it’s fair and simple.”

This view is upheld by the Prime Minister and the majority of Tory MPs, including Finchley and Golders Green MP Mike Freer. Another argument against AV is that it could triple the cost of elections – to �300million.

Meanwhile, Camden’s Labour finance boss Theo Blackwell reflected the indecision in the Labour Party.

He said: “I’m an official member of the “meh2av campaign” [on Twitter]. On the one hand, a lot of people are disgusted with Nick Clegg and we see it as all part of the power compromise [in government], even though we are quite in favour of electoral reform.

“The No campaign is run by the Tory Party and members of the Tax Payers’ Alliance.

“Quite a lot of Labour Party members will be making their decision over the next few days. Neither side has massive appeal.”

The No campaign is, in fact, a cross-party group which is separate from the Conservative Party, but it shares some of the financial backers.

o There will be a debate on AV at St Mary’s Church in Abbey Road, Kilburn, next Wednesday (April 27) at 7.30pm with Times columnist David Aaronovitch, Chris Philp, Cllr Andrew Marshall and a Labour representative, with Ham&High editor Geoff Martin acting as chairman.