MAY 5 is Ascension Day – it is also the favoured date for the General Election. Political Editor GRAHAM DINES looks at the Prime Minister's options.UNLIKE United States presidential and mid-term elections, European Parliamentary polls, and British council elections, the date of the General Election in Britain is not fixed.

MAY 5 is Ascension Day – it is also the favoured date for the General Election. Political Editor GRAHAM DINES looks at the Prime Minister's options.

UNLIKE United States presidential and mid-term elections, European Parliamentary polls, and British council elections, the date of the General Election in Britain is not fixed.

It gives enormous power to the Prime Minister of the day to hold it when he or she considers there is the best chance of winning. Theoretically, parliaments can last five years before a poll has to be held, but in practical terms they usually take place on the fourth anniversary or just beyond.

The 1959 parliament lasted five years, because Sir Alec Douglas-Home – who replaced the ailing Harold Macmillan – wanted time to bed in before going to the country. His ploy nearly succeeded, because Harold Wilson just sneaked home.

Wilson's majority was barely sufficient to carry out Labour's programme and within 18 months, another poll was held – and he stormed to victory.

John Major clung on for the full five years in 1997 and was humiliated at the polls.

Cutting and running before the five years can be disastrous. Ted Heath did that in 1974 – less than four years after he had pulled off a shock victory over Wilson – in the "who governs Britain" election in the middle of the miners' strike.

Heath lost.

Jim Callaghan was overtaken by events. He ignored the advice of colleagues and the messages from the opinion polls and declined to hold an election in October 1978, four years after Labour's re-election.

He held on to the following year, the Winter of Discontent caused uproar, he lost a vote of confidence in the House of Commons, a rampant Margaret Thatcher led the Tories to victory and Thatcherism was born.

Elections are always held on a Thursday, which until the mid 1950s was the traditional half-day closure of shops and factories which allowed the workers plenty of time to vote.

Although there are 52 Thursdays in a year, it seems odds on that the next General Election will be on May 5, just under four years since Tony Blair achieved his second landslide. The 2001 poll had been delayed five weeks from the Prime Minister's preferred date of early May because of the catastrophic outbreak of foot-and-mouth disease throughout much of rural Britain.

Winter months are unpopular for elections. Householders don't want to be canvassed in the dark, either on the doorstep or by telephone. Unless there is an over-riding constitutional need – such as a defeat on a motion of confidence in Parliament – that effectively rules out January, February, the beginning or March, November and December.

Bank holidays rule out Maundy Thursday and the Thursday after the Easter weekend.

July's out because of school holidays in Scotland as is August with most Britons on holiday at some stage.

The August holiday month eliminates September because three-and-a-half weeks notice needs to be given before a poll is held to allow nominations to take place and ballot papers to be printed and distributed for those voting by post.

October is not popular with party managers or seaside hotelliers because the annual conferences have to be cancelled at short notice – although I suspect the public would be actually thrilled not to suffer the three-week bore by the sea.

Since World War II, there have been two General Elections in February, one in March, one in April, three in May, four in June, one in July – immediately after victory in Europe in 1945 – and four in October.

Although Britain's presidency of the G8 group of the world's richest nations in the first half of this year won't hamper an election, Tony Blair's presidency of the European Union between the end of June and the middle of December effectively scuppers those six months.

The business of the EU cannot be bogged down by a British election, or the outside possibility of a change of UK government.

Which brings us back to May. Tony Blair is known to favour the fifth, even though it's Ascension Day – politicians won't let the little matter of the third holiest day in the worldwide Church's calendar get in the way of a bid for power.

May 5 is also the date of the county elections when, among other, voters in Suffolk and Essex will be choosing a new council for four years. An election could not be called for the end of May during the build-up to the county elections – it would be an administrative nightmare for council staff responsible for administering elections.

Now to hedge my bets. It is just possible the Prime Minister might allow the county polls to take place to ensure there is not major shift in opinion away from Labour to either the Tories or the Liberal Democrats.

This would give voters still angry at the Iraq war to take it out on Labour council candidates before asking them to endorse a third Blair term in office.

If he does delay it until June, the date would be either June 9 or 16 because of the looming EU presidency.

The other, and certainly the constitutionally greater, consideration is: where's the Queen during any possible election period?

Whatever day the Prime Minister is considering Downing Street staff will have already checked – or manipulated – the Queen's diary to ensure she is in the country both to dissolve Parliament and to hand seals of office to the incoming government.