The Professional Firefighter's Union says the lack of leadership demonstrated immediately after the February earthquake in Christchurch last year is unforgivable.
Southern branch president Dennis Fitzmaurice says a report in August last year on how the service coped during the devastating quake made 40 recommendations - none of which have been implemented.
Mr Fitzmaurice is calling for the removal of the area's regional commander Rob Saunders, whom he says has lost the confidence of union members.
He says the report was critical that it took about two hours after the 6.3-magnitude quake hit for senior management staff to be in contact with the southern communications team.
Mr Fitzmaurice says the report praised fire fighters for performing above expectations - but the lack of leadership shown by senior managers is unforgivable.
In a statement on Friday, the Fire Service says it is implementing all the improvements identified in the review. Many have already been completed, but some are still under way.
It says organisational changes do not happen overnight and it is unrealistic for the union to expect that.