Over the past decade, the ALP has shed many votes to the Greens. The number-crunchers in the NSW Right, desperate to boost the ALP's primary vote, now want some of them back.
Calling the Greens dangerously naive 'extremists', they threaten to withhold preferences from their partners-in-government at the next election.
They have decided to try to shore up their own base by aggressively differentiating themselves from the Greens.
And the Greens are vulnerable. Some supporters are dismayed at their unwillingness to compromise on asylum seekers, and without the reassuring presence of Bob Brown, they are a party that needs to find a platform, post-carbon pricing. ALP preferences are crucial to maintaining their position in the Senate.
The dangers of this feud are obvious for both parties, but the most obvious flaw in the ALP's strategy is that it will not win a single vote back from the Coalition.