Ian Austin
Personal letter from former Gordon Brown aide and minister sent to dozens of key marginals
Austin, who is to become trade envoy to Israel, accused the shadow chancellor of telling "a complete lie".
Former minister says he won't contest the general election.
Dudley North MP called party "a sewer" of anti-Semitism and was said to have lashed out at party chairman.
Parliament working with National Cyber Security Centre to secure computer network.