Any moves to privatise the service will lead to a decline in work undertaken in the public interest and undermine confidence in the justice system, the union has warned. The proposals are under consideration by the quinquennial review team, which is expected to report to minister by the end of the month.

On behalf of 1,300 forensic scientists, Prospect is calling on the government to abandon any suggestions of a sell-off or part privatisation and allow the service to remain an executive agency of the Home Office.

Prospect negotiator Mike Sparham said: "There can be no benefit in allowing the service to be run by a profit-driven organisation. This will inevitably lead to vital forensic work being viewed as being too costly, not being carried out or undertaken in a way that undermines quality.

"Although the FSS currently charges the police for its services, a vast amount of additional work is provided for free because of the public sector ethos within the organisation. Not only would this disappear, our members fear much of the high profile and sensitive work they undertake will be considered unprofitable or labour intensive.

"While we acknowledge the need to invest in FSS’ assets, we do not believe that a transfer from trading fund status to a Government owned PLC will provide the required investment as previous examples such as Consignia and Railtrack have shown."

Rather than sell off the expertise within the service, the union believes there are a number of alternatives for raising additional capital that have not been explored sufficiently by the review.

For example, individual partnership projects with private sector organisations to sell surplus services, the use of special financing vehicles to increase borrowing, and private finance initiatives on a ‘design, build and finance’ only basis which would leave the FSS with responsibility for day-to-day organisation and management.