Leaked by the Tories, no doubt, to distract from the self-impose schism brought about by the EU exit referendum, and disgust from the marginally less inhuman tories over the benefits cuts.
The fact that Sadiq Khan is listed as "hostile" makes a bit of a nonsense of Zack Goldsmith's tediously repetitive claim that electing Khan as Mayor would result in some sort of Corbynite "experiment" with London.
http://www.theguardian.com/politics/2016/mar/23/labour-mps-hostile-corbyn-leaked-party-document
List at the bottom.