Labour's leadership campaign has taken another brutal turn, after Blairite members of the party were described as a "virus" by one of the country's biggest unions.
On Wednesday the Communications Workers' Union (CWU) gave Jeremy Corbyn's insurgent leftwing campaign a boost when it urged its members to pick him as Ed Miliband's replacement.
In a statement, Dave Ward, the general secretary of the CWU, said: "There is a virus within the Labour Party and Jeremy Corbyn is the antidote."
The attack on the centre-right of the party has already triggered a backlash, deepening the rift between the wings of the party.
Corbyn also won the backing of the the Transport Salaried Staffs' Association (TSSA) today. He has already secured the support of Unison and Unite.
In a video message, Ward said: "There are no quick fixes for the Labour party, but there are some easy decisions and choosing Jeremy as its leader should be one of them.
“We think that it is time for a change for Labour. The grip of the Blairites and individuals like Peter Mandelson must now be loosened once and for all. There is a virus within the Labour Party and Jeremy Corbyn is the antidote.
"We reject the notion that Labour needs to move to the centre ground of British politics. The Centre ground has moved significantly to the right in recent years. We do not see arguing for fairer wealth distribution, decent jobs with good pay, terms and conditions and a substantial increase in affordable housing for the next generation as a left wing agenda."
The TSSA today announced it was backing Corbyn for leader and Angela Eagle for deputy leader. TSSA leader Manuel Cortes said, "We are delighted that our union is backing Jeremy for Labour Party leader and Angela as Deputy. People are fed of machine politicians who never give an answer. Jeremy is straight talking and puts forward sensible policies which resonate with ordinary people.
"Jeremy is clearly articulating why we must end the austerity quagmire and that Labour's economic policies must move on from failed neoliberalism. He and Angela also support bringing our railways back into public ownership. That is why I will be strongly urging our members to vote for Jeremy for leader and Angela for deputy".
The union will also be asking its members to give their second preference votes to Andy Burnham for leader and Tom Watson for deputy.
Corbyn will discover whether he has beaten Yvette Cooper, Andy Burnham and Liz Kendall to the leadership on September 12.