Labour politicians have defended leader Tony Blair despite an expected reduction in the party's majority in the House of Commons from four years ago.
Health Secretary John Reid said the Labour victory predicted by the exit poll would be a "hugely successful" result in the circumstances.
"I think that given the scrutiny that's been placed on Tony Blair, and some unfair traducing of his character as well, that the sort of figures, the ball park we are talking about is, I think, hugely successful," he told BBC 1.
"If the exit poll was accurate . . . if it does mean that Labour has got a third successive term, with Tony Blair as its leader, it's never been done before; it's historic."
Former home secretary David Blunkett said getting an unprecedented third term "will be an endorsement of the direction we have been taking". But he acknowledged there was an "underlying issue" with politicians not being held in high esteem, adding: "We have to get closer to the electorate."
Mr Blunkett said the possibility of a reduced majority had to be seen in the context of two previous "avalanche victories" for Labour.
Challenged about whether he was likely to be back in office in a new Labour Government, he replied: "Well, we'll see what the prime minister wishes me to do tomorrow."
Defence Secretary Geoff Hoon acknowledged Iraq had been an issue in the campaign, but insisted it was "nothing like" as significant as the economy and public services.
Mr Hoon also predicted that Labour stood to make gains in a string of marginals.
But Tory MP Boris Johnson said the result reflected the "slow, sad political extinction of Tony Blair.
"I am going to declare that this election is not a landslide for Tony Blair. For the first time in three elections we have not got a landslide for Labour. . . . It is a wonderful thing that the British public have finally not given this guy a landslide; it's time he didn't have a landslide.
He said Mr Blair would be quickly ejected by Labour backbenchers "consumed with self loathing" over the Iraq war "They will turn on him and they will use Gordon Brown as their defence," he said.
Kenneth Clarke, the Tory former chancellor, suggested that his party and the Liberal Democrats would perform better than predicted in the exit poll.
"I find your exit poll very boring," he told the BBC. "It is exactly what the pundits were forecasting and I think we are going to do rather better than that. I think you'll find the Liberals will do rather better than you are predicting."
Liberal Democrat president Simon Hughes said that, on the basis of the exit polls, it would be the party's best share of the vote since it was formed in 1988.
"If we get a Labour majority, but with this share of the vote, they would have lost their authority in terms of who voted for them - barely one in three of the population."