Parliamentary deadlock

It was fascinating to watch the results roll in. Polls closed at 10 pm in Britain and it wasn't until early the next morning before the result was mathematically certain, confirming the exit polls from the night before: No party would have a majority of the 650 seats in the House of Commons. The Conservatives won the most seats (306) and received the biggest share of the vote (36.1%), but it wasn't enough. The incumbent Labour Party dropped 6 points (to 29%) and a net 91 seats from the 2005 election (to 258). The Liberal Democrats won 23% of the vote, one percentage point better than last time, but finished first in only 57 seats, a net loss of 5.

Usually, one party wins a majority of seats. If the incumbent party doesn't win, the sitting prime minister and cabinet resign, the Queen invites the leader of the winning party to be prime minister and form a government, appointing other party leaders as cabinet ministers (usually those who served as "shadow" minister during the party's time in opposition).

But no party has a majority, so what now? Gordon Brown, the incumbent prime minister, gets first shot at forming a governing coalition. He remains prime minister until he resigns or there's a successful vote of no confidence. (The last successful attempt was in 1979, which the Labour government of James Callaghan lost by one vote. This led to the dissolution of Parliament, a general election, and the victory of Margaret Thatcher and the Conservatives.) To stay on, Labour would need the backing of the LibDems and the nationalist parties from Wales (Plaid Cymru), Scotland (SNP), and Northern Ireland (SDLP). That would likely require a coalition government, with LibDem leaders given several key seats in the cabinet. But LibDem voters are likely to feel betrayed if their party goes into government with the bunch they wanted out.

If Labour can't hang on, the Queen would call upon Conservative leader David Cameron to form a government, because his party is closest to a majority. He's already in talks with the LibDem leader Nick Clegg, but he doesn't necessarily need LibDems to agree to a coalition. It would be enough for them to agree not to support a no confidence motion. The Tories have enough votes to survive as a "minority government" if the Liberal Democrats abstain from a vote of no confidence.

The Tories could also try to form a governing coalition with the support of the Welsh and Scottish nationalists, which would be unlikely, since the Conservatives are Unionists and historically have opposed devolution as well as independence.

The final option would be another election, right away, or after one of the above scenarios limps along for a few months. A second election could result in a clearer outcome. Yesterday's vote would give tactical voters enough information to elect their least worst option. A supporter of a candidate that finished third or lower might choose their preferred option among the top two finishers in their constituency.

One of the arguments in favor of continuing the First Past the Post method of deciding elections -- most votes wins the seat, no matter how tiny the percentage of the total vote -- is that it turns even a slim plurality of the popular vote into a decisive majority of seats. That didn't work this time, with three very evenly balanced parties. Using the Alternative Vote (also known as Instant Runoff Voting) would likely have produced a decisive outcome. My sense is that there would have been fewer seats for Labour and more for the Conservatives and the Liberal Democrats, as supporters of both parties would have preferred the other to another term for Labour.

The outcome will cause financial turmoil and international uncertainty, but for us political junkies it's heavenly.

MORE:

• Grauniad: Downloadable election results
• 2010 British election result database: Direct link to downloadable spreadsheet
• BBC Election 2010 results map: Drill down to country, region, and constituency.
• BBC: How to vote in a general election
• BBC: In pictures: The history of the Swingometer: Using percentage vote swing in early election results to predict a national result
• ConservativeHome: A collection of blogs by public officials, policy analysts, campaign consultants, and activists -- lots of speculation on how this hung parliament will play out
• Samizdata: The Scottish dimension to the UK political scene: "It is time to cut Scotland loose, both for its interest, and more to the point, for those who want to see the back of the Scottish Labour Party and its arm-lock on UK affairs for the past decade and a half."
• Samizdata: And the winner is: none of the above and a plague on all their houses: "Now I'm watching [Boris Johnson] say that the voters hate all the politicians, and have found a way to make all of them suffer."
• Hot Air: Hung Parliament in British elections
• The Foundry: Gordon Brown must not cling to power: "Britain needs strong leadership both at home and internationally, and the electorate has voted emphatically for change."