417. Jurisdiction of adjudicator.

It is open to a defendant in enforcement proceedings to challenge the decision of an adjudicator on the grounds that he was not empowered by the Housing Grants, Construction and Regeneration Act 1996 to make the decision1. For example, a decision purportedly made under the statutory provisions relating to the binding nature of an adjudicator's decision2 by an adjudicator in respect of a contract which is not a construction contract3 at all, or which is a construction contract entered into before Part II of the Housing Grants, Construction and Regeneration Act 19964 came into force5, is not a decision