The Fire Brigade Union (FBU) for the South East has called on the government to scrap plans for regional fire centres after criticism from MPs.
The select committee said the project to replace control rooms put the future of an efficient fire service system at "substantial risk".
A centre in Hampshire will cover Kent, Buckinghamshire, Berkshire, Isle of Wight, Surrey, Sussex and Oxfordshire.
The government said the centres would cut costs and improve response times.
The communities and local government committee said the programme to replace fire control rooms has been "poorly executed and badly managed" but said it should still go ahead.
Paul Watts, regional FBU officer, said: "The building in Hampshire has been sitting idle to the cost of £1.5m a year.
"In this current climate that's a lot of money going to waste.
"We want the government to scrap the whole scheme.
"We believe the money should be invested in local centres."
But despite the committee's concerns it concluded the plans should still go ahead.
Fire Minister Shahid Malik said: "We accept that there have been problems in delivering the project.
"However, through the changes we have already made - many reflected in the committee's recommendations - I believe the project is in a better position than ever before."