Blair cannot escape the ghastly mess in Iraq, but his opponents might not benefit from it

Tony Blair rarely seeks to highlight the war against Iraq. In his speech a week ago, billed as the unofficial launch of Labour's election campaign, there was not a single word relating to the conflict. Occasionally Mr Blair dares still to make the moral case for the war. With the publication of the photos showing British soldiers torturing Iraqi prisoners even these broad-brush arguments will be harder to deploy.

In what way are these bleak images part of a moral crusade? Last year Mr Blair was deeply depressed by the photos of US soldiers abusing prisoners. Now he faces more acute anguish closer to home.

The parallels with the US torturers are not precise. In the aftermath of the photos from the Abu Ghraib jail last year there was, and to some extent still is, confusion over culpability. Some of the US soldiers claimed they were carrying out instructions issued by the political leadership in Washington.

The British government, previously preening itself on the enlightened approach of its troops, would not be mad enough to encourage or condone wild misbehaviour. This is an important qualification, but not one that will register widely in Iraq and the Middle East. The images are far too similar to those from Abu Ghraib for opponents of the war to reflect on a subtly different political context.

Even before the publication of the latest photographs I have noticed a change in the private mood music applied to Iraq among Mr Blair's close allies. One told me recently that it has all been "ghastly". Another said that, "of course the choices relating to Iraq had been nightmarish". This is not a sensational acknowledgement that Mr Blair had made, in their view, a series of monumental policy errors. It is, though, a contrast to the previous strident assertions that the war was the right thing to do, that most voters were not interested anymore and that was the end of the matter.

Most of the time Mr Blair declares disingenuously that it is time to move on from Iraq, as if the story had reached a satisfactory conclusion. The publication of the photos is a vivid reminder that a Prime Ministerial exhortation cannot erase the nightmare or even keep it away from the front pages for very long.

But the broader political repercussions in Britain are complicated and do not necessarily work against Mr Blair. Most immediately, no political leader has sought to make capital of the photos. At yesterday's Prime Minister's Questions both Michael Howard and Charles Kennedy condemned the images without making any link with Mr Blair's support for the war.

It is difficult to see how even Mr Kennedy could do so. Any troublemaking intervention would have appeared as a crass attempt to benefit from the situation: "This shames our country and puts our troops at risk. Vote Liberal Democrat". Both leaders were wisely restrained.

More widely, the Conservatives, the only other party capable of winning an overall majority at the next election, are trapped still by their original support for the war. Almost certainly Mr Blair will have made a pragmatic calculation from the very beginning: If he opposes the war and the conflict is successful the Conservatives will benefit hugely. At the same time Conservatives will be in no position to gain support if the conflict does not go to plan.

I am not suggesting that this was Mr Blair's only calculation or was necessarily uppermost in his mind, but he never acts without assessing the impact on political opponents. Indeed I would almost argue that the former Conservative leader, Iain Duncan Smith, was responsible for Britain going to war. If Mr Duncan Smith had been an opponent, rather than an ardent supporter of war, Mr Blair would have acted more cautiously as he has done over Europe where the Conservative leadership is firmly opposed to the new constitution and the euro. In crude electoral terms, Mr Blair's pragmatism is partially vindicated. Some of the Conservatives' natural supporters admire him for his stance and contemplate voting Labour. Allies of Mr Blair noted that Labour's poll rating went up during the week that he held a summit with President Bush last November. They argued, rightly in my view, that there are some voters who respect Mr Blair more for his close association with the most powerful leader in the world.

In some ways Mr Blair is still fighting the political battles of the 1980s. He will never contrive a situation where he is rebuffed by a US president as Neil Kinnock was during his embarrassingly short meeting with President Reagan in the build-up to the 1987 election.

Of course there are others, including many readers of The Independent, who are horrified by Mr Blair's relationship with President Bush, the latest photographs, the growing death toll in Iraq and much more besides. The most likely beneficiaries of this still intensely felt outrage are the Liberal Democrats, opponents of the war from the start. With the Conservatives in some turmoil and the re-emergence of Iraq as a news story the Liberal Democrats have political space.

What is more they are using that space constructively. Charles Kennedy has never been burdened with an excess of gravitas and yet almost in spite of himself he has put together a substantial policy programme, more credible and coherent than in recent elections. Oddly Paddy Ashdown had the gravitas, but his policies had not been as clearly thought through.

Even so, the Liberal Democrats have a bigger obstacle to overcome than is widely realised. They occupy precariously ill-defined terrain. It was much more straightforward for the old SDP/Liberal Alliance in the 1980s when Labour had moved far to the left and the Conservatives to the right. In such propitious circumstances the third party still failed to make a breakthrough. Now with Labour on the centre ground and the Conservatives limping erratically in that direction the third party is in some ways much more constrained.

As I mentioned last week, I continue to meet Labour supporters who plan to vote for the Liberal Democrats because of the war. I have since met several cabinet ministers who tell me they met friends over Christmas who want to give the government a kicking for the same reason. Yet Britain has a voting system that is of little use for a third party. That was the harsh reality in the 1980s and is still the case today.

In some ways, yesterday's Prime Minister's Questions were a rehearsal for the forthcoming election campaign. For much of it, Mr Blair and Mr Howard battled it out over their plans for taxation and spending, the Prime Minister versus the only alternative Prime Minister available to voters at the next election. Mr Blair got the better of Mr Howard with ease by exposing in detail the weaknesses of the Conservatives' so called "savings". At one point he declared defiantly: "The choice is between Labour's investment in public services and Tory cuts". At the end of that session Conservative MPs had good cause for alarm. But if I were Mr Kennedy, I would have been worried too.

s.richards@independent.co.uk