The Prison Officers Association takes issue with the condition of vehicles belonging to the service.
President Cerron Richards says too many vehicles are not working and the State has done nothing to address the problem.
Mr. Richards yesterday wondered if the State intends to privatise the service, hence the refusal to fix the vehicles.
Mr. Richards said these arrangements make one wonder about the plans of the government.
National Security Minister Stuart Young says the claims are without merit and must be dismissed.
But Mr. Richards insisted the fleet of vehicles owned by the Prison Service is not in good condition and even the Prisons Commissioner is driving a rental.
Minister Young is reported as saying he is disappointed with the approach taken by Cerron Richards, who has in the past been told to bring to his attention any concerns and they would be addressed.