Prime Minister Gordon Brown's governing Labour Party has seen its opinion poll lead cut in half, a survey in The Sunday Times newspaper showed.
Labour's support had dropped from 42 percent to 39 percent, while the main opposition Conservatives have risen from 32 percent to 34 percent, according to the poll.
The survey could affect party mood as the British political conference season gets into full swing.
The Liberal Democrats, whose conference kicks off Sunday in Brighton, were on 15 percent, up from 14 percent, the poll showed.
Labour's conference is in Bournemouth from September 23-27, before the Conservatives gather in Blackpool from September 30 to October 3.
Labour have overtaken the Conservatives in opinion polls since Gordon Brown took over as prime minister from Tony Blair on June 27.
The predicted "Brown bounce" has lasted as the premier has earned praise for his assured management of three straight crises: the failed terror attacks in London and Glasgow, widepread flooding and the foot and mouth outbreak.
Meanwhile as the poll lead vanished, Conservative leader David Cameron has come under attack from the right flank of his party, bashing his drift towards the centre ground.
The Liberal Democrats have seen their opinion poll ratings slump under leader Menzies Campbell, a former Olympic sprinter.
Pollsters YouGov interviewed 1,842 adults online across Britain on Thursday and Friday.
They found 60 percent of voters wanted a referendum on the controversial European Union treaty, with 40 percent believing it to be the same as the abandoned EU constitution in all but name. The constitution was shelved after being rejected in Dutch and French referendums.
Last Mod: 16 Eylül 2007, 23:27