Blair is expected to offer a sweeping look at the party's achievements over the past decade and also assure that it can win a fourth term of government.
According to excerpts of his speech, released in advance, Blair will also use the occasion to emphasize that the values which first carried Labour to victory in 1997 will be the cornerstone of its campaign for the next British election, widely expected in 2009.
"The scale of the challenges in 2007 dwarfs what we faced in 1997. They are different, deeper, and bigger," Blair is expected to say.
The party has suffered in recent polls with the electorate unhappy over issues such as the war in Iraq and recent scandals that have dogged the Blair government.
The prime minister had said last year that he would not run again; last month, he said he would be stepping down within the year.
Aides to the prime minister said on Monday evening that Blair would not be naming the date he would leave office, and his biographer said no one should expect him to anoint a successor.
"He'll come across as a statesman," author Anthony Seldon said.
The reception Blair will receive at Tuesday’s conference, a gathering attended almost exclusively by his party's rank and file, is likely to be warm.
But the issue of who will take over from Blair will be in the minds of many watching.
"He's been a good prime minister for the last 10 years, undoubtedly”
Faiz Yunis, a Labour lawmaker
"He's been a good prime minister for the last 10 years, undoubtedly," said Faiz Yunis, a Labour lawmaker on a local London council.
"He's brought in a lot of reforms ... but most people want to see him move aside, and they want to see a nice, smooth transition. They don't want it to be messy."
Gordon Brown, Blair's treasury chief and the man most likely to succeed him, used his conference speech on Monday to outline his agenda for the party he wants to lead.
Brown received a standing ovation of nearly three minutes, and the most sustained applause during his remarks came when he said he would relish taking on a resurgent Conservative party, led by 39-year-old David Cameron.
Blair has said that he wants to focus on policy rather than political intrigue during the conference, and that he wants to talk about education, health and the economy.
That may not wash with some party members. Asked what he would like to hear Blair say in his speech, delegate Hugh Scullion was blunt.
"He's leaving," said Scullion, a union official from Scotland. "In the interest of the party, the sooner he sets the date, the better. There's the need for a change in political direction."