THE SNP are demanding a full public inquiry into the Tory “texts for contracts” scandal – and have piled the pressure on Boris Johnson to publish all of his own correspondence.

The Conservative leader indicated during Prime Minister’s Questions that he would do so following revelations about his contact with Sir James Dyson.

Johnson personally promised the Tory donor he would “fix” an issue over the tax status of his employees after being directly lobbied by the entrepreneur, it was reported earlier.

In the Commons, the Prime Minister insisted he had nothing to hide under questioning from Ian Blackford and appeared to agree that he would release “all personal exchanges” on coronavirus contracts by the end of the day.

Last year, it was reported the Prime Minister is using an encrypted messaging service in which messages can be permanently deleted.

WATCH: Boris Johnson claims Ian Blackford's dog is 'more sensible' than he is

The SNP Westminster leader has now penned a letter to Number 10 to demand action.

Blackford writes: “The 'texts for contracts' scandal at the centre of your government is growing more and more serious with every day and with every allegation. This morning's revelations regarding your own personal texting exchange with Conservative party donor, James Dyson, have added to genuine and growing public concern about privileged access and process in the operation of covid contracts.

“As Prime Minister, you are now at the very heart of this scandal. It is now clear that we need a comprehensive, independent public inquiry to achieve transparency and accountability. Alongside that full and thorough inquiry though, the public also deserve answers and transparency right now.”

He adds: “This afternoon at Prime Minister's Questions, you gave a welcome and specific commitment to ‘immediately' publish all your personal correspondence relating to Covid contracts.

“This commitment is now in the record of the House of Commons. The public have the right to expect that you will stand by this commitment – if there is nothing to conceal then I presume you will follow through on this promise. I therefore look forward to and expect the full publication of all your personal exchanges on Covid contracts by the end of today.”

READ MORE: Boris Johnson told Sir James Dyson he would ‘fix’ tax issue in text

At Prime Minister’s Questions, Johnson brushed off suggestions there had been any wrongdoing regarding his correspondence with Dyson.

He stated: "There's absolutely nothing to conceal about this and I am happy to share all the details with the House, as indeed I have shared them with my officials immediately.

"It's thanks to that immediate action that we've been able to roll out ... to help the people of the whole United Kingdom to get access in record times to the vaccines on which we all depend."

He added: "We've had to work at incredible speed and I think the people of this country understand that it's sometimes necessary to act decisively to get things done."

The BBC said it has seen a series of text messages between Johnson and Dyson after the Brexiteer entrepreneur was unable to get the assurances he was seeking from the Treasury.

The exchanges took place in March 2020, when the Government was appealing to firms to supply ventilators amid fears the NHS could run out.