A leading polling expert has given his backing to the country’s only Green MP to retain her seat at the next election.

Peter Kellner, president of the YouGov polling company, has predicted that Caroline Lucas will avert a Labour gain in Brighton Pavilion and successfully defend her 1,252 majority.

Bookies currently have Ms Lucas and her Labour rival Purna Sen neck-and-neck, while a constituency poll by Tory strategist Lord Ashcroft in July similarly had the pair in a close-run finish.

Adam McGibbon, national Green Party general election campaign manager, said the party was not “taking anything for granted” but that Mr Kellner’s backing was “encouraging”.