Opposition Labour Party leader Ed Miliband's approval rating has hit a record low, a poll showed Sunday, raising further doubts about his ability to unseat Prime Minister David Cameron in a national election in just over six months.

The survey was published after polling data last week showed Miliband's left-leaning party is set to be nearly wiped out in Scotland, a traditional stronghold, and after a string of polls suggested a long U.K.-wide lead it enjoyed over Cameron's Conservatives has shrunk.

Derided by the press as socially awkward since he assumed the party's leadership in 2010, Miliband, an Oxford-educated career politician with the demeanor of an academic, is seen by some in and around his party as an electoral liability rather than an asset.