entryism

Their aim is to #KeepCorbyn but insiders say they should be barred
Members of far-left parties and the Greens are defying Labour’s rules to join the party to defend Jeremy Corbyn, insiders
As much as I want Corbyn to win, this is only because it would signal to me that Labour as a whole has begun to turn back into a viable Opposition once more. If a load of non-Labour members pay 3 quid and vote in a leader Labour members don't want, not only is it unfair to the party members, but it also tells us nothing about what Labour is.