Commentary: Ministers are on such shaky ground

With the Tories' withdrawal from the Butler inquiry, the Government's position on its decision making over war in Iraq has become even more untenable.

The Conservatives' move not only discredits an already damaged effort to get at the truth, following the controversy over the Hutton Report. It also comes at a point when the Government is on very shaky ground over its refusal to reveal the Attorney General's advice on the legality of the war. And the two issues - the use of intelligence and the legal opinion - are inextricably linked.

The only arguments made so far for why the Government should not publish Lord Goldsmith's advice are at best weak. They are either that to publish would be to break precedent, or that just as private citizens do not have confidential letters from their lawyers made public, neither should the Government.

These days it is no longer acceptable for a government, under crown prerogative, to demand that the public and the state support it unquestioningly in making war. The rules of the game have changed, and the Government seemed to acknowledge this when it tried to persuade the nation of its case for war by publishing dossiers on Iraq's weapons of mass destruction.

The intelligence dossiers formed one of the Government's key justifications for war. But its other justification was the Attorney General's formal legal opinion that the war would be legitimate under international law. What very few have commented on is the necessary connection between the two documents.

In fact, the claims made in the public dossiers may well have been crucial to the Attorney General. Whether an attack on Iraq was legal was never going to be the sort of question that has a single, unambiguous answer. But the greater appeared the imminent threat to British interests, the easier government lawyers were going to find it to draft the answer the Prime Minister wanted.

In short, the Government needed to convince its lawyers of the same things it was trying to convince the media, MPs and the public of.

Without the evidence on WMD, Lord Goldsmith's advice might have been very different, and the same is true for the United Nations. The war would not necessarily have become legal even if the UN had said it was, unless the UN itself could have defended its decision by arguing Iraq presented an immediate threat to world peace.

Of course, the shakiness of the Attorney General's reliance on the Government's WMD evidence does not necessarily mean that he was pressurised politically. It is claimed by some that his advice changed, but legal opinions do change as issues develop.

It may be important that a senior Foreign Office legal adviser, Elizabeth Wilmshurst, resigned because she believed that the legal advice supporting war was wrong.

It may be true that the Cabinet relied instead on advice from a professor at the London School of Economics already known to have a more robust position on the legality of the war. Then again, this may all just be evidence of differing professional views.

But to assess any of this properly, we need to know two things: the intelligence evidence on WMD and how the Government used it, and the exact nature of Attorney General's advice.

Especially now that the Tories have further discredited Butler's somewhat limited inquiry process, we may never know much more than we do now about the Government's own understanding of the intelligence. But if it refuses to release the Attorney General's advice, we will be entitled to be very sceptical of the entire enterprise.

Because the Government went to war without a UN warrant, it needs to have done so because of what a lawyer would call its "due diligence" about the threat Iraq posed.

If the Attorney General's final opinion gave firm support to the war, this, presumably, is what it would have attested. So did it?

David Robertson is Professor of Politics at St Hugh's College, University of Oxford