The war in Iraq has scuppered Tony Blair's chances of becoming one of the most effective British prime ministers of the 20th century, according to a new study.
An article for BBC History Magazine today finds that despite his reforms to the public sector over the past ten years, Mr Blair's decision to take military action against Saddam Hussein has undermined his hopes of becoming one of the great UK leaders.
Instead, Margaret Thatcher tops the poll of the best prime minister of the last 100 years, compiled by historian Francis Beckett. She shares the highest place with Clement Attlee who led a Labour government between 1945 and 1951.
The war on Iraq has already taken its toll on Mr Blair's popularity - a YouGov poll after the 2005 general election found that 26 per cent of the natural Labour supporters who failed to vote for the party, did so because of their opposition to military action.
But today's analysis suggest it will also have a major impact on his standing in history, overshadowing the significant achievements of having the biggest ever Labour majority, being re-elected twice and leading major reforms in health and education.
"Blair made a lot of progress in his chosen direction right up to the time of the Iraq war," said Mr Beckett, who has written a book on the Labour prime minister.
"The private sector has now been brought even into the running of schools and hospitals, and since the Conservatives agree with it, this will probably be a relatively permanent change.
"The unpopularity of the Iraq war, and the fact that the reasons given afterwards for going to war were not those given at the time, have undermined Blair's ability to implement his vision, probably permanently."
By contrast, the historian views Mrs Thatcher, who was Conservative prime minister between 1979 and 1990, as the best leader for her ability to drive and then manage widespread social change.
"Margaret Thatcher took one sort of society, and turned it into another sort of society. She broke the Attlee settlement, which had lasted more than 30 years, largely by force of will," he argued.
"Today few people under 40 remember a time when trade unions were a real force in the land; when the public sector controlled large swathes of the economy; when local councils controlled education and other local services; when benefits were considered rights of citizenship.
"The defeat and destruction of the once-powerful National Union of Mineworkers was a key moment in the history of the last half decade."
The best prime ministers (scores from five to 0):
- Margaret Thatcher - 5
- Clement Richard Attlee - 5
- Edward Heath - 4
- Winston Churchill - 4
- Harold Macmillan - 4
- Sir Henry Campbell-Bannerman - 4
- Robert Arthur Talbot Gascoyne-Cecil [later Lord Salisbury] - 3
- Herbert Henry Asquith- 3
- David Lloyd George- 3
- Stanley Baldwin- 3
- James Harold Wilson- 3
- Tony Blair- 3
- James Callaghan - 2
- Arthur James Balfour - 2
- Andrew Bonar Law - 1
- James Ramsay MacDonald -1
- Sir Alec Douglas-Home - 1
- John Major - 1
- Robert Anthony Eden - 0
- Neville Chamberlain - 0