Yesterday's Butler Report may have fleft Tony Blair in the clear. But, as Political Editor Chris Lloyd reports, the real judgement is still to come.

THREE inquiries, three reports, three exonerations, but two more tests come today for Tony Blair, and they are potentially more telling than yesterday's Butler Report.

They are the by-elections in which ordinary people go to the polls in the two formerly safe Labour seats of Leicester South and Birmingham Hodge Hill.

No-one seriously expected the Butler Report to cause the ground to shake and the sky to fall in. After all, Mr Blair appointed Lord Butler and gave him his remit. Mr Blair may be many things, but he is not suicidal.

Yet, he cannot influence by-elections so easily. If Labour loses both, Mr Blair will face an extremely uncomfortable weekend with the Sunday papers full of Gordon Brown's plotting to overthrow him.

But should the Conservatives come third in both, then Michael Howard will be seriously worrying over the weekend.

It says much about the current peculiarity in British politics that it is seriously suggested that a government ten months away from a General Election might squander majorities of 13,243 and 11,618 in by-elections.

It also says much that it is seriously suggested that, with a government untrusted because of unpopular foreign affairs, the main opposition party - the Conservatives - might slip into third place in both those contests.

Should Labour finish runners-up in both by-elections with the Tories taking third in both, it is hard to see which of the leaders would be the biggest loser.

Once again, the real winners may be the Liberal Democrats, who last year in Brent East overturned Labour's 13,047 majority.

But the peculiarity continues: following the LibDems' successes in the local and European elections, the bar of expectation for them is now set so high that one victory tomorrow night will be a good performance - but still leave them wondering why they didn't bag the brace.

The reason for this peculiarity can be discovered, of course, in yesterday's Butler Report. Not in the detail of the report because inquiry-fatigue set in long ago and very few people will read it in full.

In Westminster yesterday, some observers felt that Butler's detailed criticism of Mr Blair's style of government was "devastating". But in the world outside the bubble, the fact that an inquiry has discovered Mr Blair does business informally, on a sofa, without taking minutes and probably with his jacket off and top shirt button undone, will cause very little devastation.

But all voters will pick up an impression from yesterday's events. And it will only serve to reinforce the the impression that they have picked up from previous inquiries.

Mr Blair was exonerated by the Butler Report. He was also exonerated by the Hutton Inquiry. And he was exonerated by the Parliamentary Intelligence and Security Committee investigation. In fact, Mr Blair is exonerated on a very regular basis by all whom he asks to examine him.

Not that those exonerations exonerate him completely. Indeed, the Hutton Report turned out to be such a ringing exoneration that it was treated with suspicion verging on scepticism. Rather than washing him whiter than white, it appeared to be a whitewash.

The lingering impression is that Mr Blair took the country into an unpopular war with an unpopular ally for a reason - Saddam's possession of weapons of mass destruction - that hindsight cannot justify.

The lingering impression is that Mr Blair's judgment on the WMD issue was wrong. With each inquiry, and with each day elapsing without WMD being found, that impression stains.

Some people will accept that Mr Blair acted in good faith, that given the intelligence reports - which Butler says he did not manipulate or exaggerate - he had to act.

Many more people will agree with Mr Blair's wider analysis: "I cannot honestly say I believe getting rid of Saddam was a mistake at all. Iraq, the region, the wider world is a better and safer place without Saddam.''

Yet regime change - as positive as it may be - is not why Britain went to war. Britain went to war because Saddam with his illegally-held weapons was an immediate threat (before the war, one Cabinet minister whispered to The Northern Echo that it would soon come out that Saddam was able to hit London).

Saddam turned out not to be such a threat. Mr Blair's judgment must be questioned and his reputation must be stained - however much he acted in good faith and however many other reasons, less headline-worthy than '45 minutes from destruction' there might have been to justify war.

For Mr Blair at the moment, the stain is so obvious that he cannot escape it. Everywhere he goes, it follows him.

This week was supposed to belong to Gordon Brown and the public services. On Monday, the Chancellor outlined his spending review for the next three years - it was effectively how Labour's third election win will be financed, and it offered a glimpse of the kind of country Mr Brown hopes/expects to inherit from Mr Blair some time before 2008.

As spending reviews go, it was fantastic (unless, of course, you happen to be one of the 104,000 civil servants who are to be sacrificed to pay for it all). It was full of fantastic figures. A £62bn increase in public spending with 20,000 extra community wardens tackling crime and another 120,000 childcare places making the very best available to the very young. There even seemed to be a pledge to eradicate world poverty by 2013 although, dazzled by the other baubles on offer, that might have been a misreading.

But by Wednesday, Monday's news was very old, blown off the agenda by yet another inquiry into Iraq, yet another exoneration for Mr Blair, yet a deeper impression of a stain on his judgment.

Iraq has stalked Mr Blair's every move. Every time the focus has switched back to schools and hospitals - which have undoubtedly improved during his term of office - Iraq has reared up and stolen the spotlight. Suicide of a scientist, mistreatment of prisoners, helicopter gunships firing on a sacred mosque...

Yesterday, though, brings an end to the inquiries. And, in Iraq, power has been handed back to the Iraqis. And the number of deaths of both civilians and soldiers is slowly falling. And Mr Blair has been exonerated (again). And summer is just around the corner. Even the weather must improve some time soon.

Come October, Butler and Mr Blair's latest exoneration will appear as distant as Hutton and Mr Blair's last exoneration does today. The stain, although still visible, will be fading. The country will be gearing up for an election. Schools and hospitals will be the battleground. To tax or to cut will be the issue.

Iraq, of course, could blow him off course at any moment, but if today's two tests pass off with only one defeat (in Leicester, probably), Teflon Tony will re-appear in the autumn stained by experience but without too much sticking to him. After all this, he will still be favourite to win a third General Election.