Met Police Commissioner Sir Bernard Hogan-Howe is due to give evidence to the Home Affairs Select Committee on the Andrew Mitchell "Plebgate" affair.
Keith Vaz, MP, Leicester East (Lab) says the commissioner has questions to answer.
A report out today says David Cameron brought in the the wrong person to investigate 'Plebgate'.
Andrew Mitchell has written a piece in which he has accused the police of trying to destroy his career in a smear campaign.
A police officer who claimed to have witnessed Andrew Mitchell's 'rant' at Downing Street is being investigated by the police watchdog.