As this may be my last column before Tony Blair formally announces his retirement, it seems polite to devote it to a critical appreciation of what the second-longest-serving Prime Minister in modern British history has, and has not, achieved during his ten years in power. But courtesy is, alas, no longer in the national character of modern Britain. It therefore seems appropriate that the two politicians most responsible for the brash, unrestrained, materialistic society that is Britain today have both been hounded out of office without so much as a word of thanks from the people they helped to liberate and enrich.

The almost unanimous reaction to Margaret Thatcher’s departure in 1990 was “good riddance” and the same phrase can now be heard almost everywhere about Tony Blair. Instead of the crowds “screaming for one last encore” that Mr Blair’s star-struck spin-doctors had imagined, all we hear are howls of hatred and contempt.

For example, I overheard a conversation this week on a train from Oxford to Reading. Two semi-drunken squaddies, apparently just returned from Iraq, reflecting on the front page of an evening paper with a big smiling picture of the Prime Minister at his tenth anniversary celebrations: “That f***ing bastard, what’s he got to grin about? He nearly got us killed for no reason anybody can think of” – followed by phrases that cannot be printed in a family newspaper, even in this vulgar age.

Since nobody seems to care much about Mr Blair any longer, this may not, after all, be the right moment to survey his career. To do that properly will require more time and historical perspective, just as it did after Mrs Thatcher resigned. The only question of interest today about Mr Blair’s departure is what it will mean for the man who finally takes control of Britain, perhaps next week: Gordon Brown.

For Mr Brown, there is good news and bad in the contemptuous, unsentimental way that Britain is dispensing with the services of T. Blair. The good news is that Mr Brown, once he actually becomes Prime Minister, will almost certainly be welcomed by the voters, instead of suffering the slump in popularity predicted by the hypothetical opinion polls that got so much publicity in the past few months. The even better news is that Mr Brown will arrive at No 10 with more freedom of action and fewer rash promises made to interest groups within his own party than any prime minister in living memory.

I have often predicted in this column that Mr Brown would achieve the “orderly handover of power” that he had always hoped. And I argued, in contrast to other political commentators, that the so-called “failed coup” by the Brownites last September was, in fact, an egregious Blair blunder that Mr Brown turned into a tactical masterstroke. But even I did not expect that the Blair-Brown transition would be as smooth and uncontroversial as it has turned out. Mr Brown has gained enormously from this orderly transition. The avoidance of any serious internecine conflict in the past few months has been beneficial for Mr Brown not just because appearances of disunity are unpopular with the public. In fact, voters are usually less “shocked” than media pundits when they discover that politicians are sometimes prone to argue among themselves. What, then, is the real benefit to Mr Brown from enjoying a “coronation” instead of a genuine contest?

To ensure victory in a closely fought election, Mr Brown would have been forced to make all sorts of public promises to Labour activists, trade unions and special interest groups – and perhaps most damagingly to Mr Blair himself. But as things have turned out, he has given absolutely no hostages to fortune before taking power. He has not even had to cut any special deals with other ministers and backbenchers. He does not have to cope with a powerful and intrusive Chancellor threatening to break down the door to No 10. He does not have to worry, like John Major, about Mrs Thatcher’s backseat driving, nor manage a Cabinet full of hostile “wets”, as she did throughout her first term. He does not have to kowtow to trade unions like James Callaghan, nor beat off challenges from powerful figures within his own party like Harold Wilson – the list could go on and on.

The upshot is that Mr Brown has more freedom of action than any politician in living memory at the start of his prime ministerial career. The bad news is that Britain will expect him to use this freedom of action – and do so quickly – to dissociate himself from the blunders of Mr Blair. If Mr Brown fails to repudiate Mr Blair's errors, his honeymoon with the voters will be a very brief one – and he will soon find himself blamed for everything that went wrong in the Blair decade, while sentimentalised memories of the charming former prime minister will get the credit for most of the things that went right.

The most important and obvious of these blunders is, of course, Iraq. Now that Mr Brown has finally won his long-awaited prize – and has won it, crucially, without making public promises to protect Mr Blair's legacy or reputation – he no longer has any excuses for silence or ambiguity on Iraq. More specifically, he must repudiate Mr Blair’s subservience to the foreign policy of the Bush Administration, most obviously in Iraq, but also in Iran, Israel and Palestine.

Even if operational and diplomatic arguments dissuade Mr Brown from immediately announcing a date for the withdrawal of British troops from Iraq, he can and must distance himself from Mr Blair’s obsequious attitude to US foreign policy. While Mr Brown may be reluctant, like every British prime minister before him, to break with America, he does not have to do that.

Luckily for him, all he has to do is break with one man, who may still be bear the title of President but is now virtually powerless, isolated in the White House and despised by his own people. By detaching himself immediately from President Bush’s foreign policy, Mr Brown would not be turning against America, but doing just the opposite. He would be respecting American public opinion and falling into line with almost every serious politician in Washington. Most importantly, he would be allying himself with the next president of the United States, whoever he or she may be.

Repudiating the Bush-Blair foreign policy legacy is now the top priority for any American politician who wants to run for president in 2008. The same will be true in Britain when Mr Brown has to face the voters in 2009.

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