Rachel Riley claims a tweet published by Laura Murray caused her serious harm Ms Murray, who took role as Labour's complaints chief in 2019, denies the claim Row began after an egg attack on Jeremy Corbyn during a London mosque trip Countdown star Ms Riley is suing former Corbyn aide Ms Murray for libel at court Former Labour staffer's tweet described Ms Riley as 'stupid and dangerous' and accused her of saying the then Labour leader 'deserves to be violently attacked'