We hear that the trade union comms chief was enjoying a leisurely Guinness on a recent trip to Dublin when he was rudely interrupted by the ramblings of a drunk. 'You're him, aren't you? You're Grant Mitchell off the TV,' slurred the confused local. O'Brien's assertion that he was not a fictional EastEnders character fell on deaf ears.
In true amateur paparazzi-style, the local proceeded to take pictures of the reluctant star on his mobile phone. O'Brien tells us he made a quick dash for the exit.
'The guy was completely barmy. I do bear a slight resemblance to Ross Kemp - we are a similar height and we both have no hair - but he's a lot posher than me.'
He adds that his wife is a big fan of the show and 'I've always wanted to be in EastEnders'. Casting directors take note.