His mauling of Nigel Farage has drawn favourable comparisons with Jeremy Paxman in his pomp – and even sparked suggestions that he might replace the current affairs rottweiler on Newsnight.
But while James O'Brien's performance may have put the LBC presenter in the national spotlight for the first time, regular listeners will know the former newspaper showbiz reporter has a taste for verbal combat.
After O'Brien discussed comments made by Elen Rives, the former partner of the England and Chelsea star Frank Lampard, about her and their children moving out of the family home into a smaller house in 2009, Lampard rang in and had a forceful exchange with O'Brien.
Boris Johnson clashed with O'Brien over a postponed fire brigade strike in 2010, saying that Mr O'Brien's audience were being treated to the "wrath" of a journalist deprived of a story
However, others have pointed out Mr O'Brien's "charm" and "openness" when speaking to members of the public.Reuse content