A YouGov poll in the Sunday Times newspaper puts Labour at 36%, the main opposition Conservatives at 33% and the smaller Liberal Democrats at 23%.
If the percentages are the same when the nation casts its ballots on Thursday, that would translate into 369 parliamentary seats for Labour, 181 for the Conservatives and 65 for the Liberal Democrats.
In that case, the newspaper said, Labour would have a majority of 92 seats - well down from the 161-seat advantage it enjoyed after its June 2001 election landslide, but still more than enough to form a government.
Another poll, in The Independent on Sunday newspaper, gave Labour 39%, the Conservatives 31%, the Liberal Democrats 23% and other parties 6%.
A Mori poll in The Observer, based on respondents who said they were certain to vote, gave Labour 36%, three points ahead of the Conservatives, with the Liberal Democrats on 22%.
Meanwhile, an ICM poll for The Sunday Telegraph put Labour support at 39%, the Conservatives at 31% and the Liberal Democrats at 22%.
It said if that were the outcome on Thursday, Labour would win a third successive landslide victory with a majority of 146 seats.
Conservative leader Michael
Howard is trailing in the polls
In The Mail on Sunday, a BPIX poll of those certain to vote on Thursday put Labour on 37%, the Conservatives on 33% and the Liberal Democrats on 21%. Other parties took 9%.
After a week in which his decision to take Britain into the Iraq war became a major issue, The Sunday Times poll found that 46% thought Blair was a "liar" and that 50% felt he was not a good prime minister.
Only 26%, however, thought Conservative leader Michael Howard would make a good prime minister - and 52% believed Liberal Democrat leader Charles Kennedy could not handle the top job.