Why a single poll cannot tell the story

Yesterday saw the release of the first two opinion polls since last week's leaders' programme on Sky News and Channel 4.  The first poll was conducted by YouGov and published in the Sunday Times.  It suggested that Labour had a four-point lead, which would give it a choice in terms of who it could turn to in order to govern.

Later that evening, a second poll was released by the Daily Mail and ITV News conducted by Comres.  This poll showed a four-point lead for the Conservatives, which would give them a shot at forming another government.

Two polls, conducted around the same time, showing two different stories.

Examining the trendlines with six weeks to go

And that's it.  Parliament has been prorogued for the final time, and will be formally dissolved tomorrow.  MPs are returning to their constituencies to do what needs to be done to keep their jobs.  Dubious promises will be made, tough questions will be dodged, and personal insults will be hurled.  But ultimately, 650 MPs will be allowed into Westminster to shape the next five years of the country's future.

The polls give us a snapshot of the national mood, but every poll will show that there are still a number of voters who haven't yet made up their minds.  But what about those who have either made up or otherwise changed their minds in recent months?  Where have they been going, and what will the House of Commons look like if it continues?

Betting markets suggest second UK election possible in 2015

In the UK, you can place a bet on just about anything.  You can bet on the result of this afternoon's QPR-Everton match (Everton is the favourite as of this writing).  You can bet on who will replace Jeremy Clarkson as co-host of BBC's Top Gear (not sure whether 12/1 for Piers Morgan or 50/1 for Nigel Farage is more ridiculous).  You can bet on the winner of this year's Eurovision Song Contest (40/1 for the UK winning, meaning if I bet £1, I lose £1).

Of course, you can also bet on 7 May elections here in the UK.  You can bet on any possible outcome, including which party will finish with the most seats in the House of Commons, what kind of government will be formed, who will be leading that government, and the fate of the party leaders in their jobs both as leaders and as MPs.  You can even bet on who will win in each of the 650 constituencies, and it's the odds that bookmakers are offering on these kinds of bets that tell us the most about what to expect once the polls close in 45 days' time.

The effect of Britain's new major parties

At the last general election in 2010, the three main parties had 88% of the vote.  That figure for the same three parties is now down to 72%, as three new parties have come to the forefront of British politics.

If the UK used a form of proportional representation, we would expect the UK Independence Party and the Green Party to have dozens of seats in the House of Commons.  However, with the first-past-the-post system that we have, neither of these parties is expected to get into the double digits on current projections.

Even though these representations of these two parties are expected to be tiny after the election, their uprisings are still having an impact on the balance of power across the UK.