The couple and their three children were put under surveillance without their knowledge by Poole Borough Council in Dorset for more than two weeks using powers under the Regulation of Investigatory Powers Act (RIPA).

The family only found out about the spying when a school admissions manager told them.

The authority said it used the legislation to watch the family at home and in their daily movements because it wanted to know if they lived in the catchment area for a school which their three-year-old daughter wanted to attend.

Human rights pressure group Liberty called the spying "disproportionate" and "intrusive".

James Welch, legal director for Liberty said: "It's one thing to use covert surveillance in operations investigating terrorism and other serious crimes, but it has come to a pretty pass when this kind of intrusive activity is used to police school catchment areas.

"This is a ridiculously disproportionate use of RIPA and will undermine public trust in necessary and lawful surveillance."

The anonymous mother told the Bournemouth Echo she was shown the surveillance record, listing her movements from February 13 to March 3, including school runs with her children and the routes they drove.

The angry family told the newspaper the surveillance team wrote down detailed notes such as "female and three children enter target vehicle and drive off" and "curtains open and all lights on in premises".

The RIPA legislation allows councils to carry out surveillance but only if it suspects criminal acts have taken place.