The college, where Prospect represents more than 70 lecturers and other staff, is an award-winning leader in fire and emergency response training and one of the largest operational fire and rescue training colleges worldwide.
The Department for Communities and Local Government formally launched the sale of the college – currently run as a trading fund – this week. A condition of the sale is that it must continue to function as a training centre.
Prospect negotiator Phillippa Childs said: "The college is based in the middle of the Cotswolds, with training facilities considered to be the best in the world. But it's falling to bits. Government spending constraints have meant that no money could be spent on the infrastructure or recruitment, and staff have also faced a pay freeze."
Childs said that it used to be mandatory for all fire brigades to use the college for training, but problems had arisen when brigades were given the option of using other, private training providers.
"Many current problems stem from the fact that the college has had to operate as a commercial venture within the constraints of government ownership.
"However, our members are worried about being transferred out of the public sector, not least because of the potential impact on their pay, pensions and other terms and conditions.
"It is also outrageous that a national resource such as this, which provides vital training to a key emergency service, should be privatised and thus subject to market forces which rely on making a profit in order to function."