Speaker heard talking about Trident missile test going wrong
Speaker John Bercow is caught on mic saying that picking a fight with a select committee chairman is "a stupid thing to do".
His comments came after exchanges in the House of Commons about reports a Trident missile test went wrong last June.
Defence Secretary Michael Fallon declined to confirm or deny the reports and said he had not decided whether to accept an invitation from defence select committee chairman Julian Lewis to appear before the committee in private on Tuesday to answer questions.