Love and politics are the two great figures of social engagement. Politics is enthusiasm with a collective; with love, two people. So love is the minimal form of communism.
I am not too happy with terms like “the left”, to be honest. And I don’t use it much…. if by “the left” you mean people who are committed to peace and justice and freedom and so on, there can’t be elements of the left opposed to workers’ movement, at least under that definition.