Research from Plymouth Uni points out that Labour would only have secured a majority of 48 if the 2005 election had been held with new constitutency boundary changes.
So, Brown will have to win bigger than Blair -- despite a stronger SNP, a weaker Welsh Labour, and a Tory party that won the popular vote in England in 2005 -- to equal Blair's majority of 66.
If Labour doesn't have to have an election until 2010, why does Gordon Brown need to go to the country to seize a larger majority? If he's practicising big-tent politics, what reforms does he have in mind that would threaten large backbench Labour revolts that require a larger majority than 66?
What if he calls the election, and the Tories are able to outspend Labour enough to return Labour with what they already have, a 60-seat majority, or a 20-seat majority, or a hung Parliament? He'll look like a worse electioneer than Blair.
The question is more, should there be an election at all?
Brown is working his way through a second checklist. This time the list is of Conservative positives ... have-a-go heroes, British jobs for British workers, zero tolerance, tougher controls, stricter codes. If the early polls are any guide, this too has been popular, feeding a second boost for Brown ... The hegemonic centre ground project is back in business, with the Tories shoved to the right, the Liberal Democrats eclipsed and the left effectively destroyed. Some may call the result a one-party state on Japanese lines. A few may even whisper about fascism.
Prime ministers call elections under one or more of three circumstances: because the government lacks a majority; because it has used up the bulk of its legislative timetable; or because it faces a defining crisis. None of these criteria applies in any way today. A 2007 election would be an act of opportunism and no little vanity. It would elevate campaigning above governing. It would be an election driven by pollsters and partisans, not by the people or by propriety. It would be a dereliction of responsibility. It would be morally wrong.