August's ICM poll shows Labour at a 19-year low and the Liberal Democrats significantly up. Labour support has dropped four points in a month, to 31%, the lowest figure recorded by ICM for the Guardian since just before the 1987 election. Voters have switched to the Liberal Democrats, who are up five points since July, to 22%. With the Conservatives rising marginally (up one) to 40% this gives them a lead of 9% over Labour, enough for a narrow majority in the Commons at a general election.

[Guardian] [Poll breakdown]