Union leaders are threatening action under data privacy laws after Bradford became the first council to install 'spy' trackers in its bin lorries.

Public services union UNISON claims the controversial new £60,000 tracking system is "over-the-top" and "unnecessary" and may be in violation of the Data Protection Act.

UNISON also says many staff are still unaware that the surveillance equipment has been introduced.

The advanced computer system links of all the Council's refuse vehicles to a central computer allowing each vehicle's location to be pinpointed in the city at any time.

Bradford Council is the first in the country to introduce this kind of technology to its street-cleaning operations.

Liz Devlin, chairman of UNISON's Bradford branch, said: "I think the system's introduction is completely over the top and unnecessary.

"There has been no agreement between staff and the Council about procedure for the system's operation.

"The introduction of any monitoring system without a clear procedure for what it will entail is in breach of the Data Protection Act.

"We will be reporting this breach to the data protection commissioner and I will seek an audit of all of the Council's data protection procedures."

Miss Devlin also claimed that evidence from this surveillance technology had been used in a disciplinary hearing in the cleansing department, which she said was another violation of the Data Protection Act.

However, Damian Fisher, Principal Cleansing Officer for Bradford Council, denied the accusations, saying: "To my knowledge the tracking system has not been used in any disciplinary procedures and all staff were informed verbally of the system being introduced."

The refuse vehicles have been fitted with 96 General Packet Radio Service (GPRS) units which transmit to a central computer giving details of where they are in the city.

The results are displayed on a large plasma screen at the cleansing department depots in Harris Street, Bradford, and Stockbridge, Keighley.

Mr Fisher said: "The system has made a real difference already in the short space of time that it has been in force.

"Our collection service is now far more efficient. If we receive a complaint saying that we have missed a collection then we can pinpoint the nearest refuse vehicle on our screen and dispatch them to collect it.

"It has also made a difference to the health and safety of our drivers. The system includes a panic button connected directly to the police. If any of them get into trouble they can notify the authorities quickly."

Mr Fisher said another factor which led to the system's introduction was to reduce insurance claims against the council's cleansing department.