A BIG shift in British public opinion over the past ten days has produced a clear majority in support of the military action in Iraq.

This was confirmed by two new polls yesterday. But — and the buts are always important with opinion polls — Tony Blair cannot take public attitudes for granted.

The scale of the shift is striking. As recently as a fortnight ago, according to regular ICM polls, there was a near two-to-one margin against a war on Iraq (53 to 29 per cent). That has shifted to 55 per cent approving of military action, compared with 37 per cent disapproving, according to a new ICM poll in the News of the World.

A series of YouGov internet surveys point to a similar, and growing, shift and current balance since early March, when, as Populus polls for The Times showed, public support for military action was heavily dependent on a further United Nations resolution.

This change is not surprising since, whereas previously people were asked “what if” questions, now they are faced with the reality of British troops in action, and dying. So a “rallying round” is to be expected, and has occurred at the start of previous wars.

Moreover, Mr Blair seems to have impressed many by his leadership on the issue. According to YouGov, more than a quarter of the public were more convinced of the need for war by his national broadcast on Thursday evening.

The existence of a clear majority for military action, and a revival in Mr Blair’s ratings, contradicts the “not in my name” slogan or claim of the anti-war campaigners that the Prime Minister is out of touch and is not speaking for most British people.

However, the 36 to 37 per cent against, according to the latest two polls, represent a substantial minority of the public, notably middle-class professionals and centre-left activists.

Moreover, this is a higher level of opposition than at the start of other wars. Admittedly, according to Gallup, 31 per cent disapproved in October 1950 of British troops going to fight in Korea.

And there were deep divisions over Suez in 1956. But in other cases, disapproval was less. Margaret Thatcher had the support of between two thirds and three quarters of the public for her handling of the Falklands Conflict in 1982, with a quarter, or often less, opposed.

And the American-British military action to retake Kuwait in early 1991 was backed by between three quarters and four fifths of voters. And well over two thirds supported the Nato action against Serbia over Kosovo in 1999.

So, even after the start of fighting, Mr Blair faces a more divided nation than during previous fighting.

Moreover, the very scale and speed of the recent shift of opinion also has a downside, suggesting that attitudes are volatile. The margin in favour of action could, and probably will, increase if fighting intensifies.

But, while the British public appears to accept that there will be casualties, attitudes depend heavily on the outcome.

These divisions also suggest that, postwar, Mr Blair and Labour should not expect the type of boost that Mrs Thatcher had after the Falklands, though that was linked with an improvement in the economy.

This time, the economic outlook is more clouded, with taxes already rising next month. Mr Blair has won an important tactical victory in the battle for public opinion, but he still faces many strategic doubts, notably over his relations with President Bush and over domestic policies.

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