The unprecedentedly high figure - thought to be a record for any democratic politician - will set the seal on what promises to be a euphoric Labour conference in Brighton this week. Asked whether the premier was doing a good job, 93 per cent said yes, 3 per cent thought he was doing a bad job and 4 per cent answered "don't know".
The fortunes of Mr Blair, who arrived in Brighton yesterday, are in sharp contrast to his main political rival. The same Labour research found that only one-third of those polled thought that William Hague, the Conservative leader, was doing a good job.
Labour strategists are aware that the findings have been boosted by the Prime Minister's capture of the popular mood in the aftermath of Princess Diana's death. One senior party source said they are "unsustainable". There is concern that the Prime Minister will start to be seen as infallible - a view that could drastically change as soon as he makes the smallest error.
The leadership does not want the conference to be too triumphalist. Mr Blair will remind the party faithful of the hard work that still needs to be done. On Tuesday, when he will be the first Prime Minister to address a Labour conference for 19 years, he will call for the modernisation of Britain's institutions, to make the country a "model 21st century nation". He will seek to build on the legacy of Princess Diana by stressing "compassion" as a key national quality. He has not decided whether to mention the Princess directly.
Early drafts of his speech indicate that he will identify creativity, compassion and an outward-looking nature as central British values. He will argue: "Now is the time to draw to a close the years of decline, the years when the leaders of this country presided over the graceful fading of outdated institutions.
"We have the chance to reshape our identity to offer the world so much more than our past, to seize the future and make it happen for us rather than let it happen to us." He will receive a further boost tomorrow when conference delegates back his plans to reform the annual policy-making get-together into an event resembling a public relations showcase for Cabinet ministers.
The leader's programme for reform, Partnership Into Power, will be approved by a substantial majority, ending the traditional and often bitter conference wrangles that have humiliated former Labour prime ministers.
In future, the new national policy forum, meeting in private, will determine a "rolling programme" of strategy to be rubber-stamped by conference.
Officials are considering ending the annual seaside bash a day early or starting a day later in future because there will not be enough business to last a week.
Although the week's events will be seen by the outside world as a "coronation" of the Prime Minister, ministers will this week queue up to warn delegates that "hard choices" lie ahead as the Government adheres to Tory spending plans up to 1999.
In particular, the Health Secretary, Frank Dobson, will say there is no more money for the NHS, over the extra pounds 1.2bn for next year announced in Chancellor Gordon Brown's first Budget. He will warn of lengthening waiting lists in hospitals this winter as pressures mount.
David Blunkett, the Education Secretary, will announce a new literacy scheme for children, but will offer nothing more to critics of his plans to introduce tuition fees in universities.
Meanwhile, William Hague faces criticism over suggestions that he may not oppose Labour's plans to abolish a hereditary House of Lords. He also faces possible embarrassment over his ballot of Tory members asking them to back him and his plans for party reform - the details of which will not be published until after next month's Tory conference in Blackpool. Tory activists resent the way in which both issues have been linked into one question.
The party does not know how many members it has. It has distributed about 300,000 ballot forms through local constituency organisations. One member since 1955 yesterday complained that he had finally received his ballot paper - too late to use it.
A Central Office spokesman said about 100,000 papers had been returned.