"Steve, Militant Tendency did infiltrate Labour, and were expelled.
They were not Labour. They had extreme views and values that were not those of Labour."

Their views and values are immaterial in the current context of this discussion. And they were Labour. The fact is that Militant consisted of Labour Party members and were not infiltrators. They didn't just spring up when Derek Hatton was around, you know. You can't infiltrate something that you're already in. They may have been a group within a group, but that's no different from the Fabian Society or Labour Friends Of Israel or the 1922 Committee or the Monday Club. The use of "infiltrate" or "entryism" is a well-known right-wing ploy for smearing those on the left of the party. It's no surprise that they enjoy pride of place in your personal lexicon, Keith.