Although the adjudicator's jurisdiction and natural justice are the most common grounds relied on to render an adjudicator's decision invalid, fraud, duress and violation of the Unfair Terms in Consumer Contracts Regulations 1999 (the UTCCR) and the Human Rights Act 1998 (the HRA) have also been relied on by defendants in adjudication enforcement proceedings, albeit far less frequently. As with fraud and deceit, the test for duress leads to a relatively high threshold to overcome in order to succeed. Often, the UTCCR is raised in the context of domestic residential works where the contractor is alleged to have agreed with the consumer adjudication provisions.