The precedent is discouraging: after three unhappy weeks spent squabbling about taxation, parliament was dissolved by the monarch. Queen Elizabeth II is not about to repeat Charles I's disastrous dismissal of the short parliament, 370 years ago today, but she may have to tread carefully in the next few weeks if the crown is not to be dragged into another toxic argument about who has the right to run Britain.
This country has got used to yet another of the distortions of the existing electoral system, by which one party or another forms the government on a minority of the vote. It is far less accustomed to what in much of the rest of the world is the norm: a range of parties, none of them with majority support and none able to rule on its own. Yet if the polls are right, this is how things may stand on Friday afternoon.
The Conservatives, according to a story in the Guardian yesterday, are growing restless: if they win the most seats, they want Gordon Brown out immediately. But unless they win an overall majority – which by tradition brings about an immediate change of government – that demand would be unconstitutional. Gordon Brown, as prime minister, would have the right to stay put unless and until he resigned or parliament voted him out. Winning the largest minority of seats, or the most votes, does not guarantee a party power.
Two things have changed recently. First, parliament will not meet the week after the election, but a fortnight after – which in theory could extend Mr Brown's caretaker spell before a vote. Second, the cabinet secretary, Sir Gus O'Donnell, has written a guidance paper on the formation of governments. But neither of these changes is fundamental. The delayed return of parliament may allow extended coalition talks, but the real purpose is to allow the many new MPs and ministers to settle in. And Sir Gus's note codifies existing rules; it does not alter them.
This will not prevent an almighty media row breaking out if the Conservatives win more seats than Labour, but Mr Brown stays on in the hope of doing a deal to get a Queen's speech through the Commons. The Tory press will cry foul. Mr Cameron should bide his time. Tories might note that their allies in Sweden have 33 fewer seats than the largest party, the opposition Social Democrats.
In Britain, the February 1974 election is often cited, but the better precedent is 1923. Then, Conservatives won 67 more seats than Labour, but not a majority. Labour took office. True, the momentum was against the Conservatives in 1923; this time it will be against Labour. But it is parliamentary votes that count, and if Mr Brown wants to wait a fortnight to test them, the constitution says he can.
