London, July 15 : British prisoners are signing up for a National Lottery-funded project to assess and measure ancient trees in the hope that by doing so, they will gain freedom sooner than later.
The "hugging" trees program is part of their rehabilitation.
The UK Prison Service insists it does not receive funding for taking part in the five-year scheme, and that it helps prisoners to improve their maths skills.
The Times, however, quoted a TaxPayers' Alliance spokesman as saying: "I do not think this is what people imagine when the Home Secretary talks about prison being a tough place.
"Victims are led to believe criminals are being punished, not taught to hug trees," he added.
The Woodland Trust's Ancient Tree Hunt hopes to pinpoint 100,000 ancient specimens across Britain during its "Summer of Hugs".
A group hug is a recommended method of dating a tree. A British standard hug from an adult with arms outstretched, fingertip to fingertip, is about 1.5 metres, and a child's hug is roughly half that.
The Prison Service said: "Many offenders have poor literacy and numeracy skills. This is just one project that teaches prisoners serving less serious offences skills in maths, measurement and using databases, as well as teaching them to value the environment."