Steve Davies appears on BBC Radio 4
The new law requires citizens to follow the spirit of the law rather than the explicit written law. Normally, when there is ambiguity or doubt about the interpretation of a law it is decided on a case by case basis by the courts. What a general anti-avoidance law would do is give that power of interpretation to bureaucrats and agents of the state, which is a serious threat to the rule of law.
Listen to the full programme here. Segment begins 8:00.