THEY'RE changing the guard at 10 Downing Street. Today marks Tony Blair's last day as Prime Minister and Gordon Brown's first as his successor.

Mr Blair's decade in power has seen him transformed from a political pop star, heralding the dawn on a new age for Britain, to a man worn down by the pressures of office and weighed down by the aftermath of a hugely unpopular war.

As he entered office in May 1997, Mr Blair's New Labour promised "things can only get better".

On the face of it, they were right. John Major's Tory government was mired in sleaze and economic failure. The country wanted a change after 18 years of Conservative rule.

And there is no doubt that some things have got better. There are more nurses and teachers, the minimum wage has been introduced, there is peace in Northern Ireland, the economy has been at its most stable for centuries.

And yet there is a huge sense of disappointment in the way Mr Blair leaves office compared with his entrance. Sleaze is not a thing of the past under New Labour. Think of the double resignations of Peter Mandelson and David Blunkett.

The fear of terrorism has created a schism between some sections of the Muslim and Christian communities. The gap between rich and poor has grown.

Ultimately, Mr Blair's legacy boils down to a four-letter word. Iraq.

The war and its subsequent horrors will forever define Tony Blair's premiership. For a man who won an unprecedented three elections for Labour and seemed destined to break the mould of British politics, such a definition must leave him full of sadness and regret.