How we do it now

First-past-the-post (FPTP) is a 'winner takes all system' which means the proportion of the seats is often different from the proportion of votes received. Small parties such as the Greens can get several percentage points of the vote without getting a single MP.

On the results of the MORI poll we report today, Labour would get 56 per cent of the seats on 36 per cent of the votes, while the Tories will get 28 per cent of seats on 33 per cent of the votes. The Liberal Democrats suffer as usual taking just 9 per cent of the seats with 22 per cent of the votes

Problems

FPTP is a heavily regionalised system, leaving it a matter of complete chance whether your preferred candidate has a hope of winning the constituency you live in and thus whether your vote means anything. Even experts do not agree on how best to use your vote to influence parliament.

According to the Electoral Reform Society 425 out of the 659 seats could be called today with no risk of failure. 'Support for one party or another is so strong that, barring a political earthquake or personal scandal, the dominant party's candidate will win and will win comfortably,' says chief executive Ken Ritchie. In a further 54 seats a swing of at least seven per cent is needed to dislodge the incumbent. This leaves only 180 seats (27 per cent of the total) up for grabs and 800,000 citizens (two per cent of the electorate) with any chance of altering who gets to Westminster. The three main parties focus on these 'swing' voters and the issues that concern them, careless of the views of the rest of us. It is possible that turnout in this election will be even lower than last year's European elections, when more than 45 per cent of adults in Britain did not vote.

Alternatives

Canada, the US and the UK are the only developed countries to use the FPTP system. A number of alternative voting systems are used worldwide, all of which ensure that the proportion of a party's members elected to parliament is close to the proportion of votes for that party. Such systems are used to elect members of the Scottish Parliament, National Assembly for Wales, London Mayor and Assembly, Northern Ireland Assembly and European Parliament.

Many countries have moved from FPTP in the past 50 years. The most popular system globally - used in 72 countries - is 'List PR' where each region votes for a series of candidates, increasing the likelihood that your vote gives you a voice in parliament. If you vote for the Green Party, and their candidate is not successful, your vote transfers to a second preference.

Any hope?

The Liberal Democrats, the Greens, Plaid Cymru and the SNP favour proportional representation. Labour has by far the most to lose by a switch of voting system - as did the Tories through the 1980s. Before the 1997 election, Tony Blair promised to hold a referendum on electoral reform, but it has not happened.

'The existing system produces a clear "winner" and "loser" in accordance with the broad national mood,' a 1998 report of Labour's NEC concluded. Yet Labour won a huge majority in 2001 with only 22 per cent of British adults voting for them.

If a pure form of proportional representation had been used in 2001 we would have had a hung parliament. To get any bill passed the Labour government would have needed at least 62 MPs from other parties. There would be a massive power shift from the executive to MPs of all parties - and, at election time, to voters. In a recent poll, 63 per cent of Britons favoured proportional representation.