Evidence Steve?
Are you not following the debacle at all?

"Mann (Labour MP) told Harman (acting leader): "[The election] should be halted. It is becoming a farce with longstanding members … in danger of getting trumped by people who have opposed the Labour party and want to break it up – some of it is the Militant Tendency-types coming back in.
"It is pretty clear that what is happening amounts to infiltration of the Labour party."
http://www.theguardian.com/politics/2015/jul/26/jeremy-corbyn-genuine-labour-supporters-leadership-election