LONDON — British Prime Minister David Cameron's Conservatives have pulled level with the opposition Labour party for the first time in 18 months, according to a YouGov poll published on Thursday, as the economy shows signs of recovery.

The poll puts both parties on 36 percent of the vote shortly before each hosts its annual conference to set out election strategy ahead of a 2015 national vote. The last time the two parties were level was in February 2012, YouGov said.

Other polls still show a Labour lead of around 6 percentage points but that margin has been steadily shrinking after a row over party funding which has led to questions over Ed Miliband's leadership and a slide in his personal ratings.

"Labour has seen a double digit lead disappear in weeks. Its summer of discontent could turn into an autumn of despair," YouGov President Peter Kellner told the Sun newspaper which published the survey.

The Conservatives' fortunes have been buoyed by signs that the British economy is recovering after a prolonged recession — something Finance Minister George Osborne says vindicates his tough austerity policies since coming to power in 2010.