With Prime Minister Gordon Brown’s leadership came under further pressure as an opinion poll indicated that support for his Labour Party has slumped to a record low since 1943, enough to ensure a landslide victory for Tories, he has taken to “cold calling” members of general public, newspapers reported on Friday, in the latest charm offensive aimed at restoring his battered popularity.The YouGov survey, the first after the Labour’s drubbing in local elections earlier this month followed by a Parliamentary by-election defeat, put Labour on 23 points and the Conservatives on 47 — a Tory lead of 24 points.If the result is repeated in a general election due in June next year, the Conservative leader David Cameron will achieve a landslide victory, the survey for the Daily Telegraph claimed.Brown has been randomly phoning critics who have written him letters of complaint to make the point that he really does listen. While Downing St officials insisted it was not a new initiative, media reports on Friday said the idea had come from his newly appointed strategy chief Stephen Carter.Carter, a former public relations chief, wanted to “humanise” his new boss, PR Week reported.“Carter thought it was a good idea to have Brown call people personally,” an insider told the industry magazine.“Carter will choose a letter or email at random, have one of his team at Number 10 prepare a response, then get Brown to call.”The tactic, revealed on the same day as Labour recorded its worst opinion poll showing since surveys began in 1943, has been used by dozen of politicians since Jimmy Carter’s 1976 presidential campaign.It is not known how many calls Brown makes a week, but newspapers reported on Friday it was as many as two dozen.