BORIS Johnson's former senior adviser Doninic Cummings has hit back at claims that he was responsible for the leaking of private text messages between the PM and James Dyson.

The aide, who was sacked in November last year, said it was "sad to see the PM and his office fall so far below the standards of competence and integrity the country deserves."

In a lengthy blog entry, posted this evening, Mr Cummings denies being the source of the leaks,which were first published by the BBC on Wednesday.

Since the messages between Sir James Dyson and Mr Johnson emerged, the Government has been faced with growing questions and calls for an inquiry into the extent of private sector contact with ministers.

Mr Cummings accused the new No.10 Director of Communications Jack Doyle of making "a number of false accusations to media" at the request of the Prime Minister, adding that he was told in advance that he would be fingered by Downing Street for the leak.

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This morning several newspapers carried the same story, blaming Mr Cummings, suggesting the information was briefed in a coordinated way to selected journalists. 

He wrote: "I do have some WhatsApp messages between the PM/Dyson forwarded to me by the PM. I have not found the ones that were leaked...nor am I aware of being sent them last year."

He said he was "not directly or indirectly a/the source for the story on the PM/Dyson texts" and added: "Yesterday some No10 officials told me that No10 would make this accusation and told me what they believe actually happened — that Dyson’s office emailed a number of officials, including HMT [Treasury] officials, and included screenshots of the PM/Dyson texts, and that this correspondence, from roughly a year ago, was passed to the BBC.

"I do not know if this is correct.

"Officials told me yesterday that I was not copied in on this correspondence and I do not remember it (I no longer have access to my official email so cannot check this)."

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Mr Cummings said he would surrender his phone for inspection, adding: " If the PM did send them to me, as he is claiming, then he will be able to show the Cabinet Secretary on his own phone when they were sent to me.

"It will therefore be easy to establish at least if I was ever sent these messages. I am also happy to publish or give to the Cabinet Secretary the PM/Dyson messages that I do have, which concerned ventilators, bureaucracy and covid policy — not tax issues."