The Council of Trade Unions is calling for fresh legislation to address the rise of work place injuries in the Canterbury rebuild.
The number of construction sites issued prohibition notices and shut down for being unsafe last year was 224, compared to 13 in 2010.
Injury numbers have almost doubled in that time, up from 64 to 139.
Council president Helen Kelly said the number of construction accidents was increasing faster in Christchurch than anywhere else.
She said it was concerning considering the amount of work going into health and safety procedures in the region.
Ms Kelly said poor working conditions, long hours and lack of training, were not being addressed.
But Registered Master Builders Association chief executive Warwick Quinn said new initiatives were in place to tackle the problem.
He said piling on more legislation won't necessarily mean fewer workplace accidents.