The government has rejected demands for a tighter definition of the new "desirable activity" defence against compensation claims.

Baroness Ashton of Upholland, who is guiding the Compensation Bill through the Lords, admitted it was the Government's intention that it should be open to interpretation by the courts

Facing sceptical MPs on the Constitutional Affairs Committee this week, she said: "We chose the words carefully because we wanted to use an expression that's got a lot of meaning but not seek to define it, because the courts should define it.

But she added she was prepared to alter the form of words: "I'm not particularly wedded to that form of words if someone else can come along with a better one."

Baroness Ashton added that to state in the legislation which activities should be regarded as desirable would "take the issue too far".

She said: "People wouldn't take it seriously and we would see these activities wither, because parents would say they are not sure they are is being covered properly."