Some big clues in the CPGB ML's latest videos on Lenin on the Party.

Sly references to the fact they had to fight to retain their principles in the face of left opportunism, and that their Party (CPGB-ML) has won out.

Sounds a lot like classic Trot entryism. Get into a left social democratic formation in order to wage struggle against the left opportunists and hopefully emerge with more members than lost.