Labour officials say they are worried that one man could ruin the party's annual conference meeting this week in Brighton.
'We're very concerned that this man could single-handedly wipe-out all the good we are doing,' said a Labour Party insider. 'He just has to whack a trade unionist over the head again and we may as well as pack up and go home.'
Officials say the man - who has ambitions to be prime minister - has been given plenty of chances to reform but still remains unpopular with voters.
'When he makes his speech this week,' said one activist, 'I won't be taking any chances. I'll be hiding behind the nearest fridge.'