Steve Richards: Watching that sly debate on Iraq, I was struck by the parallels with the poll tax

Their distinctive approaches brought great electoral success and yet led each to catastrophe

To coincide with the 50th anniversary of Suez several columnists and historians draw depressingly neat parallels with the current nightmare of Iraq. Yet the differences between the two are more striking.

Suez arose from an exaggerated sense of Britain's might. Support for the war against Iraq was shaped by a defensively cautious view of the country's place in the world. A prime minister resigned over Suez. The prime minister that took Britain to war in Iraq continues to rule. After some agonising the Labour opposition came out against Suez. The Tory leadership supported the war against Iraq with an uncritical enthusiasm.

While watching Tuesday's depressingly sly debate on Iraq in the Commons I was struck that the parallels with the poll tax, Margaret Thatcher's greatest policy mistake, are much closer. Labour failed to make any significant electoral headway from the poll tax even though the Conservative government wasted millions and provoked fuming protests across the country.

Now it is the Conservatives that struggle for credibility in relation to Iraq. The Conservatives are stuck with their original decision to support the war and in some senior cases a belief still that they were right to do so. Privately many ministers and Labour MPs share the despair felt by voters, but cannot express it. They are trapped too. The Commons remains perversely out of step. For different reasons the same applied to the poll tax.

Thatcher's determined implementation of the poll tax and Blair's wilful desire to support President Bush are illuminating because in both cases they were logical extensions of their respective political outlooks. With a Shakespearean flourish their distinctive approaches had brought their parties considerable electoral success and yet led each of them to catastrophe.

From the beginning the tragic direction was set. Thatcher made her name by pledging to abolish the rates in the mid-1970s. From that point on she was obsessed with finding an alternative. She was a brilliant right-wing populist, making accessible the ideas of others, winning elections effortlessly. By declaring that she would scrap the unpopular rates she looked forward to more familiar plaudits when an alternative was introduced. Thatcher was capable of studying policies with a forensic focus, but in relation to the poll tax she showed no interest in the evidence when it was placed before her crusading eyes.

Blair's great genius was to make a cautious political strategy sparkle with excitement. There has rarely been a dull day since he set the stage alight in 1994. But he sparkled defensively, considering the political positioning in relation to any policy. What will the newspapers say? What will be the impact on Labour's new supporters as well as traditional voters? How will the Tories react?

His acute sense of what would be accepted by middle England voters turned Labour into an election-winning machine and enabled the Government to pass measures - from the minimum wage to huge public spending increases - that previous Labour administrations had only dreamt of implementing. It also trapped him into supporting the Iraq war.

Like Thatcher he was capable of forensic analysis, mastering detailed policies with awesome speed. In the case of Iraq he was not interested in awkward evidence. Blair was too cautious to have contemplated standing shoulder to shoulder with Germany and France, distancing himself from the US to the screaming disapproval of some powerful newspapers, the Conservative Party and possibly middle England. It was characteristic caution rather than reckless boldness that led him to his current nightmare.

In both cases MPs for the governing parties knew that their leaders were heading in calamitous directions. In the late 1980s I recall a highly astute Tory MP from a marginal seat telling me privately that the poll tax would lose the Tories the next election. He voted in favour of the measure. Similarly some Labour MPs who were alarmed at their leader's closeness to the Bush administration supported the war.

That is why Tuesday's parliamentary debate on whether there should be an inquiry into the war was one of the most dishonest for many years, as shameful in different ways as the debate that preceded the vote in favour of the war in 2003. Conservative MPs used the call for an inquiry as a device to register their distance over Iraq without admitting they were wrong to support it in the first place. Labour MPs were acting with a similar self-interested tribal servility, competing with each other to utter the insulting banality that an inquiry would undermine the morale of British troops, as if those serving in Iraq do not wonder themselves what is happening and why.

After two mediocre speeches the shadow Foreign Secretary, William Hague, rose to speak. The journalist I was sitting next to in the press gallery whispered that this would be good, at last a brilliant speaker. But Hague was not brilliant because his position was too contorted. He repeated that he supported the war and that in his view much good had come of it. Nonetheless there was a case for a full inquiry, but not yet.

The former cabinet heavyweights, Ken Clarke and Malcolm Rifkind, were sitting behind him almost exploding with frustration. They had opposed the war from the beginning and could therefore speak with genuine passion. But the Tory leadership dances around Iraq, trapped by its past, and in many cases current, conviction that it should be closer to Washington rather than more distant.

This is the final parallel with the poll tax. The main opposition did not benefit from the biggest cock-up in domestic politics since 1945. Labour was too scared to highlight the poll tax in the 1987 election although it was openly hailed in the Conservatives' manifesto. The leadership was fearful of any issue relating to local government because it had suffered from the activities of so-called "loony left" councils.

After the fall of Thatcher it was John Major that benefited politically for scrapping the poll tax. Similarly Gordon Brown will almost certainly announce a full inquiry into the war and proclaim a plethora of reforms to heighten the accountability of a prime minister. Probably the new measures will be red herrings. There were enough checks in place in the build-up to the war as indeed when Thatcher headed for disaster with the poll tax. Cabinet ministers and MPs were too timid or ambitious to challenge their leaders and then became trapped in a political culture that does not give them space to admit they had made a terrible mistake.

Still the symbolism of Brown's constitutional reforms will be potent. Major was the beneficiary of the poll tax disaster although he had supported the measure. A supporter of the war, Brown will be well placed to deal with its bleak consequences.

s.richards@independent.co.uk