LONDON (Reuters) - British Prime Minister David Cameron's Conservatives have taken a four point lead over the opposition Labour Party on the eve of the start of official campaigning for a May 7 national election, a poll showed late on Sunday.
The poll, by ComRes for ITV News and the Daily Mail newspaper, gave the Conservatives their largest lead in the polling series since September 2010.
It put them on 36 percent, up 1 point from last week, Labour on 32 percent, down 3 points, the Liberal Democrats on 9 percent, UKIP on 12 percent, and the Greens on 5 percent.
"While this is bound to be a volatile election with both Labour and the Conservatives running each other close, the longer term trends points towards the Conservatives beginning to dig in and strengthen their position," Tom Mludzinski, head of political polling at ComRes, said in a statement.
Underlining how volatile the election is, an earlier poll on Sunday showed Labour Party has taken a four point lead over Cameron's Conservatives after the first TV encounter of the campaign.
(Reporting by Andrew Osborn, editing by Guy Faulconbridge)