Blair must regain trust or be remembered solely for the suicide of a leading scientist

Fresh from his first election victory to the darkest days of the Kelly affair: the changing face of the Prime Minister portrays ravaging effects of power

On the morning of 2 May, 1997, when Tony Blair won his first landslide victory, he declared that "a new dawn has broken". Six years later, as he prepares to overtake Clement Attlee's record as the leader of Labour's longest-serving administration on Saturday, his MPs and ministers now frequently discuss what comes after Blair.

They were, of course, doing so before the death of the scientist David Kelly plunged the Government into its biggest crisis yet. For Mr Blair had already endured a disastrous few months - an unpopular war prosecuted on the basis of an increasingly questionable rationale; a botched cabinet reshuffle revealing a once-strong prime minister who was losing his grip; a succession of backbench rebellions highlighting the widening gap between a presidential-style leader and his party.

Now, increasingly, bold Labour MPs are asking, "What is Blair for?" while the Brownites are at last showing a spring in their step.

As he passes this historical milestone, what has the Prime Minister achieved?

At the 2001 general election, Labour used the slogan "a lot done, a lot to do" to help secure a second term. For the Blairites, the maxim still applies. Mr Blair's "contract with the people" in 1997 was based on five limited pledges. Four were achieved in his first term - cutting class sizes for five to seven-year-olds; reducing NHS waiting lists by 100,000; getting 250,000 young people off benefit and into work and "no rise in income tax rates". The fifth pledge, halving the time between arrest and sentence for young offenders, was achieved in year five.

In 2001, the Labour manifesto made five new pledges, which again the party was certain to meet - 10,000 extra teachers; 20,000 extra nurses and 10,000 extra doctors; 6,000 extra police recruits; raising the minimum wage to £4.20 per hour and a promise of low inflation and mortgages and sound public finances. Labour also set 10 goals for 2010, but most were rather vague - such as "opportunity for all children, security for all pensioners".

So far, so good, but Labour's record is less impressive when measured against the performance targets that were set by the Treasury.

Designed to drive up standards, Labour did help to improve numeracy and literacy but the number of targets spiralled out of control. Some targets were apparently devised on the back of an envelope. In the NHS, they distorted priorities and encouraged cheating by pressurised staff who resented the "top-down" system.

The Government claims that 87 per cent of the 366 targets set in 1998 have been achieved but this is misleading since the Government counts a target as having been met if it is only partially met and the figure only refers to the main Whitehall departments, excluding targets set for government agencies and programmes such as Surestart - a programme for young children. Meanwhile, the Tories say that the Government has met less than 50 per cent of its targets but this too is misleading. What one means by "met" and "not-met" targets is a point of argument and, as usual, the truth lies somewhere between the Government and Tory claims. The Commons Public Administration Select Committee found that 60 per cent of the 1998 targets had been achieved and that is the best independent estimate.

Ministers have cut the number of targets and in recent weeks have begun to argue that what matters most are the values that lie behind the policies. For some critics, the Government is moving the goal posts because it was getting such bad results.

On public services, the most important measure will be whether voters feel there has been an improvement by the next general election. By then, it will not be easy for Mr Blair to ask for more time to finish the job, as he did in 2001. Undoubted progress on education has been set back by the school budgets crisis. There are some real improvements in the NHS, though the voracious demands on it mean that people often fail to notice them.

Targets paint only a partial picture, and Mr Blair argues that the big picture has improved significantly since he was first elected. For example, the targets do not measure Labour's management of the economy, its biggest success story. The surprise decision by the Chancellor, Gordon Brown, to hand control of interest rates to the Bank of England helped to secure the lowest inflation, interest rates and unemployment for decades.

Britain has performed better than its European Union partners. The Government's strong economic record probably explains why the party is not doing much worse in the opinion polls, which are still relatively good for a mid-term government.

But as Mr Blair overtakes Mr Attlee, Prime Minister from 1945 to 1951, economic storm clouds are gathering. Mr Brown may have to revise down his growth forecasts for a third time, leaving a "black hole" in the public finances. A difficult government-wide spending review looms next year; further tax rises may be needed to maintain the increased investment in health and education.

Mr Blair's Third Way envisages social justice as well as economic strength, and he has done less well on this side of the equation. True, the minimum wage was a historic change. Despite the bleating by ungrateful trade unions, workplace rights have been enhanced.

The Prime Minister is reluctant to shout about it but wealth has also been redistributed through Mr Brown's tax and benefit reforms. At the same time, they are too complex and, as the fiasco over the child tax credit shows, have been introduced incompetently.

The Prime Minister promised radical welfare reform but ended up with a salami-slicing approach. Difficult areas, such as housing benefit, remain virtually untouched. Partly as a result of economic growth, the gap between rich and poor has widened - an embarrassment for a Government that has pledged to halve child poverty by 2010. Britain's underclass remains an intractable problem.

The Government has talked tough on crime, but there have been mixed results. Crime has fallen overall but violent crimes have risen slightly which, with the new trend of locking people away for longer, has had the effect of raising the prison population to a record 74,000.

Transport has been one of the Government's biggest failures. The targets in its much-trumpeted 10-year plan, such as reducing congestion, will not be met. It has taken the London Mayor Ken Livingstone's congestion charge to give it the courage to talk about road pricing. Improvements to trains remain on the distant horizon.

On constitutional reform, Mr Blair has a better record than he is given credit for. The history books will look favourably on the creation of the Scottish Parliament and Welsh Assembly, packing off the hereditary peers and incorporating the European Convention on Human Rights into British law. But Mr Blair has got cold feet about elected peers and electoral reform for the Commons. And his Government has yet to prove that its conversion to a "new localism" on pubic services is for real.

If Mr Blair were able to determine the date of his departure from Downing Street, it would be dictated not by the calendar but by his two central goals - transforming public services and ending Britain's half-hearted relationship with Europe by joining the single currency. But his warm words on Europe have not been matched by action, and the Government's long-awaited announcement on the euro in June was a missed opportunity.

After the 11 September terrorist attacks, it was perhaps inevitable that foreign affairs would dominate Mr Blair's second term. His strategy of being a bridge between Europe and America collapsed over Iraq, perhaps because he had decided long ago to fight alongside President Bush come what may. A military success was followed by problems on the ground in Iraq and a damaging failure to find the weapons Mr Blair used to justify the war.

In turn, this led to the war of words with the BBC and the tragic death of Dr Kelly which, some ministers believe, is likely to hasten Mr Blair's departure from office. It is too soon to tell whether they are right.

That the tragedy arose out of a war with the media is perhaps symbolic. Spin, Labour's greatest asset in opposition, is now its greatest liability. It has caused a highly damaging loss of trust among the voters, which could prove fatal for Mr Blair, just as sleaze proved for John Major's government. Dr Kelly's death can only corrode the Government's image further.

In politics, trust is easy to lose and hard to win back. During his much-needed break in Barbados, Mr Blair must work out a plan to regain it. Otherwise he may be remembered not for public services or the euro but for the death of a government scientist.