The lord chancellor has failed in his duty to uphold the law - by proclaiming parliamentary sovereignty over the issue of prisoner voting, according to a Labour former attorney general.

In a strong attack on Chris Grayling, Lord Goldsmith calls attention to the lord chancellor’s lack of legal qualifications, saying that his predecessors would not have made ‘this mistake’.

Grayling last Thursday responded to a European Court of Human Rights ruling by announcing a draft bill which would give parliament the option of overriding Strasbourg’s decision.

In a letter to The Times published today, Goldsmith (pictured) says that Grayling’s statement represented the first test of whether he could be trusted to fulfil his duty under the Constitutional Reform Act to uphold the rule of law.

‘He failed,’ Goldsmith says. ‘While solemnly proclaiming that he took that duty seriously he proceeded to do the opposite, telling parliament in effect that it could disregard the ruling of the European Court of Human Rights.’

Goldsmith accuses Grayling of mis-citing a dictum of Lord Hoffman in R v Secretary of State for the Home Department ex p. Simms, which concerned the Human Rights Act. ‘The issue here is about compliance with rulings of the Strasbourg court under an international convention we have entered into, which is not subject to parliamentary sovereignty.’

He said that Grayling’s invitation to parliament to decide whether to break the law ‘is hardly upholding the rule of law’.

While the lord chancellor’s advisers may be to blame ‘one cannot imagine former lord chancellors such as Hailsham, Mackay or Irvine making this mistake,’ he says.