The dark shadow of Iraq hangs over Mr Blair's aspirations for a third term

There is a logic to Tony Blair's decision to commit himself to serving a full third term. Word has reached Downing Street that the Conservatives are preparing a "vote Blair, get Brown" slogan to be deployed in the run-up to next year's expected general election. At a time when British elections are becoming increasingly "presidential" in nature, and personalities are as important as parties, this would expose a damaging ambiguity at the heart of the Labour Party. By quashing suspicions that he will stand aside in favour of his ambitious Chancellor some time during the next parliament, Mr Blair is seeking to spike the Tories' guns once again.

There is a logic to Tony Blair's decision to commit himself to serving a full third term. Word has reached Downing Street that the Conservatives are preparing a "vote Blair, get Brown" slogan to be deployed in the run-up to next year's expected general election. At a time when British elections are becoming increasingly "presidential" in nature, and personalities are as important as parties, this would expose a damaging ambiguity at the heart of the Labour Party. By quashing suspicions that he will stand aside in favour of his ambitious Chancellor some time during the next parliament, Mr Blair is seeking to spike the Tories' guns once again.

The downside of this strategy is that it will harm relations between the Prime Minister and the Chancellor, already badly frayed over the return of Alan Milburn to run Labour's general election campaign. But the Prime Minister appears to have made the calculation, no doubt correctly, that Mr Brown will not jeopardise Labour's third term by resigning and splitting the party in the run-up to an election. So as a hard-nosed political manoeuvre, it makes perfect sense.

But this cannot disguise a certain arrogance that lies behind the Prime Minister's decision. It would be unrealistic to expect an astute tactical politician like Mr Blair not to have an eye on the next election, but when there are so many unanswered questions over Iraq, it looks presumptuous. He has still not accounted for his catastrophic errors of judgement over the past two years; notably promising, and failing, to get a resolution in the UN Security Council, and then neglecting to check that the US had a post-invasion plan.

Then there is the issue of trust. We have had no apology from the PM for the way he wilfully exaggerated the threat Saddam Hussein posed to the world, despite the failure to unearth a single weapon of mass destruction since the conflict ended. There has been no comment from Downing Street on the revelations last weekend that Mr Blair was considering military action a year before the invasion. And, most importantly, there has been no sign that the Prime Minister recognises the appalling damage caused by his foreign adventurism. In the face of all the evidence, he insists stubbornly that he made the right decisions, and that he would make them again. In which case, the public has a right to know what he would do if a re-elected George Bush decided to invade Iran or North Korea. Before mapping out his next term in office, surely Mr Blair should wrap up some of the unfinished business in this one?

The Prime Minister's vow to serve a full term could be interpreted as simply a device for getting through the election campaign without being peppered with questions about succession. As he has demonstrated over the European constitution referendum, the Prime Minister is more than capable of changing his mind. Mr Blair might yet step down during the next parliament, should he win another election. However, he would do better to focus not on his own job security, but the appalling condition of Iraq and how to bridge the gulf of mistrust that separates him from his voters.