Labor’s state executive has thrown open nominations for the coveted safe seat of former Cabinet minister Michael O’Brien.

O’Brien resigned from Cabinet after Friday’s disastrous attempt to parachute Labor powerbroker Don Farrell into O’Brien’s plumb northern Adelaide seat of Napier.

Nominations for the seat – Labor’s second safest South Australian electorate – will close at 9am on Wednesday. The 20-member state executive will then choose a candidate from those who nominate.

There will be no ballot of Labor members because there isn’t time before the election for Labor to go through its normal preselection process.

The party was blindsided by O’Brien’s plan to hand the seat to Farrell. When Premier Jay Weatherill threatened to resign if the plan went ahead, and Farrell pulled out of the contest, it left Labor’s Right faction without a clear candidate for the seat.

The Right faction “owns” the seat in the factional carve up of state electorates.

No-one expected it to be available this soon – with O’Brien telling only a few colleagues about his plan to retire and hand the seat to Farrell – but it is highly coveted.

Non-aligned union chief Dave Garland has indicated he will nominate for the seat.

ALP state secretary Reggie Martin said the state executive met this morning for the first time this year.

“We could have selected a candidate today without calling for nominations but we didn’t think that was the right way to go,” he told InDaily.

The more conventional Labor preselection process takes six weeks but, with the state election on March 15, that was obviously not an option.