Labour has built a 12-point poll lead over the Conservatives, in the strongest lead for the party over the Conservatives in a decade.
The ICM/Guardian poll put Labour on 41%, up three, and the Tories on 29%, down four.
The Liberal Democrats are down two on 13% while Ukip surges forward with nine per cent, up three.
The weak Tory performance suggests David Cameron has won precious little support as a result of his pledge for an EU referendum.
The prime minister will be especially concerned at the strength of Ukip on his right flank, even after he caved in to their central demand of an in-or-out EU referendum.
The Labour lead is astonishingly wide among women. While it only enjoys a seven-point lead among men, it is 26-points wide among women, by 51% to 25%.
ICM polls are usually more generous to the Conservatives, because they assess the number of people who are likely to vote Tory but will not admit it publically.