There’s an interesting discussion on Marxmail on the Respect / SWP donnybrook, discussing how the party-building doctrine of a Marxist vanguard sometimes means they use mass organizations as recruiting and propaganda tools rather than as a way to work with other factions in a coalition and focus on the issues at hand.
Lest this seems esoteric, Respect is the British party founded by Member of Parliament George Galloway, while SWP is a vanguard party within it. But maybe not for long.