The government's auditor says the secret Whitehall letter that sealed a major deal with Nissan should be released

LONDON - The boss of the National Audit Office - the body responsible for auditing government departments and ensuring their accounts are in order - says there is no good reason for Downing Street not to release a letter sent to the bosses of Nissan prior to agreeing to build two new models at its plant in Sunderland.

Speaking to MPs from the Treasury Select Committee published on Tuesday, NAO chief Sir Amyas Morse said he "can't see any reason" why a letter sent by Business Secretary Greg Clark to Nissan's CEO Carlos Ghosn should not be released into the public domain.

Nissan agreed in October to produce the new Qashqai and X-Trail car models at its massive plant in the north-east city of Sunderland, having previously said that it may have to look to move jobs out of the city after the Brexit vote.

The news was greeted as the first major affirmation that big businesses will stay in Britain after it leaves the EU, but many questioned the way the deal was supposedly struck, criticising the government for a lack of transparency.

At the heart of this was Clark's letter.

He reportedly wrote to bosses at Nissan to tell them that the government will do all it can to assure that its UK business will "remain competitive," but at the time it was rumoured that the letter also included assurances from Clark of government financial support for Nissan.

The Department for Business, Energy and Industrial Strategy declined to comment on letter at the time, but appearing on Question Time in the week the deal was announced, Clark said that no "cheque book" had been involved in the deal. "There's no cheque book. I don't have a cheque book," he said. Essentially, Clark denied that the government has offered Nissan state aid, or any kind of financial assistance.

Pressure to release the letter has now returned after Morse's remarks and the release of a letter he sent to committee chair Andrew Tyrie in conjunction with his appearance. Morse noted that the reason the letter should be released into the public domain is that it contains no sensitive information. He also added that the letter contains no promises that could result in contingent liabilities - basically future costs - to the British public. Essentially, the government did not make any financial promises to Nissan in its letters.

Here is the key extract from Morse's letter to Andrew Tyrie (emphasis ours):

"After a meeting in Sunderland the Secretary of State for Business, Energy and Industrial Strategy wrote to Nissan on 21 October. Nissan then announced on 27 October that they will build their new Qashqai and X-trail models in their Sunderland plant. The Secretary of State for Business, Energy and Industrial Strategy then made a statement in the House of Commons on 31 October aiming to set out the assurances government had provided. After that statement my audit team requested access to the letter the Department sent to Nissan.

"I have reviewed the contents of that letter. I have also received written assurances from the Permanent Secretary that there are no other letters to Nissan on this matter and that nothing was discussed in the relevant meetings that might be understood as an additional commitment by HM Government. On that basis I am satisfied there is no identifiable contingent liability for the purpose of inquiry into whether there was an obligation to notify. We will, of course, examine the evidence again during our audit of the Department's accounts."