Frank Bruno to join N-Dubz star Dappy in backing Norman Lamb to be Lib Dem leader

Mr Lamb wants to show he has popular appeal to close the gap to Tim Farron

Frank Bruno, left, is endorsing Norman Lamb for the Lib Dem leadership (Getty)

Frank Bruno, the former world heavyweight boxing champion, will endorse Norman Lamb to be the next leader of the Liberal Democrats.

The former health minister wants to show he has popular appeal as he tries to close the gap on Tim Farron in the race to succeed Nick Clegg.

Mr Lamb has already secured the support of former N-Dubz singer Dappy, and is expected to unveil Mr Bruno, who fought Mike Tyson twice, in a video endorsement this week. “Frank Bruno is heavyweight support,” a source close to Mr Lamb said. Mr Bruno, who has suffered from depression, is a fan of Mr Lamb because of his work on mental health.

Mr Lamb will soon reveal endorsements from leading medical practitioners. A Liberal Democrat Voice poll on Friday showed Mr Farron is leading by 71 to 29 per cent among members, ahead of the first of 13 public hustings to be held in London this week.