The BBC has apologised to viewers after a 'hot mic' picked up the reaction of a man who claimed: "Between this and Brexit, we're actually f*****d".

The commentary was inadvertently broadcast on both BBC Two and BBC News channels, with the unnamed man giving the stark warning following the decision of Chuka Umunna, Luciana Berger and other MPs to leave Jeremy Corbyn’s party and sit in parliament as an independent group.

READ MORE:  Cracks appear in Scottish Labour as MPs quit

“Between this and Brexit we are actually f****d,” said the man in a live broadcast. “It’s going to be so divided … The Conservatives are going to win.”

During Umunna’s speech, a voice could be heard saying: “It’s mad, it’s mad” 

A BBC spokesperson said it was investigating the incident but they were confident it was not an employee who had made the comments.

“Due to an error, we inadvertently broadcast some background comments from another microphone during our coverage of the press conference this morning. We apologised on air once we realised our mistake.”

READ MORE: Named: Labour MPs split party in Corbyn leadership protest 

The former Labour MPs said on Monday they were leaving the party due to concerns over its direction under Jeremy Corbyn, citing concerns over Brexit, antisemitism, and the party’s internal culture.

The new group, which is not a registered political party, also suffered its own technical malfunctions following the launch after their website crashed in less than an hour after their launch.