Recalling the Shipley coup

Around the time Shipley was looking her most vulnerable as leader of the National party, mid-2001, I caught up with Colin James on entirely unrelated issues but ended up discussing the prospects of an English coup.

English seemed reluctant to move against Shipley and the media were speculating as to why. James, with his typical perspicacity, suggested that English would want to wait; that he'd move only when he though he could sustain any momentum generated by the change through to the election in 2002. However, James thought English might be forced to act earlier by a caucus anxious to avoid a rout. He was right on both fronts though the routing still occurred.

This is precisely the position Key and English find themselves in now. Brash must go, but when? The polls appear to be turning against Brash, but two years out from an election is probably too far for Key (and he's smart enough to know it) and English won't want to repeat the experience of 2002. So where too from here? Perhaps Brash will do a Captain Oates and force the issue?