The television producer turned career politician and first non-lawyer to hold the post since 1673 told the House of Lords constitution committee’s inquiry into the ancient office it is a “positive benefit” for the Lord Chancellor not to be a lawyer.

That, he said, does not mean a lawyer could not do the job, but suggested “not being a lawyer actually gives you the ability to take a dispassionate view – not from one side of the profession or the other,” which is particularly beneficial when hard financial decisions have to be made.

The Constitutional Reform Act 2005 changed the job significantly, so while the Lord Chancellor retains a role in judicial appointments and has statutory duties to uphold judicial independence and the rule of law, the incumbent is no longer head of the judiciary or presiding officer in the House of Lords. In light of this, said Mr Grayling: “I don’t think the person holding my job suffers from being a non-lawyer.”

“We don’t need a health secretary who’s a doctor in order for them to understand how the health service should shape and deliver its services. I don’t believe you need to be a practising lawyer – to understand the minutia of individual parts of the law and have experience in court – to understand the need to protect the values of our justice system.”

The rather self-serving statement put Mr Grayling at odds with many who had provided oral or written evidence to peers, including the former Lord Chief Justice Lord Judge, and Bar Council chairman, Nicholas Lavender QC, who argued the holder should be a “senior lawyer”.

The “unique” role of the Lord Chancellor, who is a “champion of the justice system” and “guardian of the constitution”, suggested Mr Lavender, makes legal expertise “essential”. Different from Secretaries of State, said Mr Lavender, he is entrusted with lead responsibility in government to maintain the delicate balance between upholding the rule of law and protecting the independence of the judiciary and, respecting the interests of the executive.

Mr Grayling characterized the role differently. It had, he said, two facets – stewardship over the judiciary and the justice system and the ceremonial role performed on behalf of the Crown. The constitutional role once performed by the Lord Chancellor, he said, is “no longer there” and constitutional issues have become the responsibility of the Deputy Prime Minister.

He saw the Lord Chancellor’s duty to uphold the rule of law as the same obligation imposed on all members of Parliament. To many non-lawyers, Mr Lavender’s lofty view of the role and suggestion it can be performed only by a lawyer may seem, if not arrogant, a trifle pompous. After all Mr Grayling is surrounded by a phalanx of lawyers to advise him on the law and the importance of the rule of law and what that means for policy.

As Mr Grayling told the committee: “One thing we do not lack in the department is a qualified lawyer”. Indeed, he said there is “an entire floor of lawyers”.

The Ministry’s legal director Rosemary Davies said the Ministry has 60 lawyers in its in-house advisory team, two legal directors and seven other senior civil service lawyers. The lawyer responsible for the judicial review reforms, she said, has been in the department for 27 years.

In addition, Mr Grayling said he can turn to the first treasury counsel, the law officers and practitioners.

Whether the Lord Chancellor should be a lawyer or not, Mr Grayling has not been the best advertisement for having a layman. Not just because, as many would argue, his strategy to cut legal aid and curb judicial review has undermined the rule of law. As Mr Grayling noted, the biggest changes to legal aid were carried out by his predecessor – “a distinguished QC” – Kenneth Clarke. But Chris Grayling’s watch has seen two shambolic criminal legal aid consultations, with U-turns on major policy areas, the loss of three judicial reviews on legal aid reforms and other challenges pending.

Policies, insisted Mr Grayling, are developed to be consistent with the rule of law, with decisions taken on the “best evidence” using the “best legal advice” and the “best judgment of what is right and fair”. But he admitted: “Sometimes we’re right and sometimes we’re wrong. We are only human”.

In post since October 2012, and despite his performance, Mr Grayling has fared better than the three previous non-lawyer Lord Chancellors, who all ended up in the Tower of London.