Labour faces subversion by Momentum and far left, says Roy Hattersley

Veteran grandee’s warning comes as row splits party over dropping and reinstatement of leftwing candidate for Watford byelectionLabour is facing the biggest crisis in its history as the leftwing pressure group Momentum tries to purge it of moderate MPs and councillors in a systematic takeover of the party, former deputy leader Roy Hattersley has warned.His dramatic intervention comes as details can be revealed of a vicious power struggle between moderates and leftwing forces in Momentum an