The Victorian secretary of the Labor Party, Erik Locke, has quit, citing branch stacking in the State party and claiming he is "embarrassed" by the party's state of affairs.

He must have a high embarrassment threshold. Locke should have resigned red-faced last November after negotiating the disastrous preference deal that gifted Family First a Senate seat with a miniscule percentage of the vote – and allowed the Coalition to cobble together its Upper House majority.

In his resignation letter today, Locke says he can "no longer explain and justify the actions going on within the party over branch stacking". It's an interesting stand, as Locke has said nothing publicly about the furore, prefering instead to help direct the battle from behind the scenes through anonymous media briefings.

There are many in the party who say Locke outstayed his wlecome by six months. His role in the preference negotiations that got Family First up in the Senate will long be remembered. Locke set himself the task of saving right wing Senator Jacinta Collins. Instead of achieving that by brokering a deal with the Family Firsters, Locke delivered the final Senate position to the religious rightists – at the expense of Collins. Then he had the gall to blame the Greens for "under-delivering" on their vote.

True to form, Locke leaked his resignation letter to ABC Melbourne morning shock jock, Jon Faine, before sending it to president Brian Daley. Today's parting shot is aimed at applying pressure on the party's admin committee to open an inquiry into branch stacking. If that happens over Erik Locke's political body, it's not such a bad result.