An influential group of MPs has today criticised the government for not telling parliament about the £61m offer it made to Nissan in a bid to persuade the car-maker to stay in the UK.

Reports that the government was offering “financial assistance” to Nissan emerged in 2016 but were dismissed by Theresa May’s deputy spokesperson at the time, who insisted there was “no special deal for Nissan”.

However, details of the attempted “sweetheart deal” emerged earlier this month after Nissan announced it was moving production of the X-Trail SUV model from its Sunderland plant to Japan, in part due to concerns around Brexit.

At the time business secretary Greg Clark called the decision a “blow to the sector and region”.

Read more: Government reveals Brexit assurances to Nissan

Following the shock move it was also reported that the government may withdraw the £61m package of support for Nissan, prompting Treasury Select Committee chair Nicky Morgan to demand that the government publish the original 2016 letter, which it did.

The committee today published a letter from Clark which confirms that the £61m was offered to Nissan in April 2018 and accepted by the car giant two months later in June.

Morgan told City A.M: “If the government is seeking to take an increasingly interventionist approach to persuade car manufacturers to remain in a post-Brexit Britain, it must be upfront about it.

“A backroom deal here and a sweetheart deal there will provide no succour to the many businesses that have not been so fortunate.”

She added that the lack of transparency around the Nissan deal, which was accepted by the car maker in June 2018, “cannot be allowed to set a precedent”.

"My predecessor as chair of the Treasury Committee asked the government in November 2016 to provide details of the financial assurances provided to Nissan to persuade it to stay in Sunderland," she said. "Details were severely lacking in the government’s response.

“When parliament shows such a keen interest in a particular issue, the government has a duty to keep it informed."

Read more: Government could pull £60m support package for Nissan

A spokesperson for Department for Business, Energy and Industrial Strategy said: “As business secretary Greg Clark said during his appearance before the BEIS Select Committee in December 2016, there were aspects of the letter to Nissan that were commercially confidential. As soon as those concerns were reduced, the letter was published without delay.

“All proposals are independently assessed by the Industrial Development Advisory Board, subject to UK and EU rules, and then published on the EC Transparency website.”