David Cameron told the Treasury’s top civil servant it was "bonkers" that a financial services firm he was lobbying for had been denied access to government-backed COVID loans.
MPs on the Treasury select committee have released correspondence between the former prime minister and a range of ministers and officials on behalf of Greensill Capital.
It comes ahead of an appearance in front of the committee by Lex Greensill, the billionaire founder of the now bankrupt finance firm.
Mr Cameron approached serving ministers and officials about the involvement of Greensill in government-backed financial support schemes during the COVID-19 crisis, lobbying that included sending text messages to Chancellor Rishi Sunak.
Mr Cameron, who was in Number 10 from 2010 to 2016, has previously said he broke "no codes of conduct and no government rules".
But he did acknowledge: "As a former prime minister, I accept that communications with the government need to be done through only the most formal of channels, so there can be no room for misinterpretation."
Correspondence released by the committee shows that Mr Cameron texted Sir Tom Scholar, the Treasury’s permanent secretary, on 3 April 2020 to say he was "genuinely baffled" at the situation regarding Greensill and the Treasury’s refusal to grant it access to the COVID Corporate Financing Facility.
He added: "Am now calling CX [the chancellor], Gove, everyone. Best wishes, Dc."
Eight minutes later, Mr Cameron sent a text to Mr Sunak, saying: "Rishi, David Cameron here. Can I have a very quick word at some point?
"Call any time on this number."
That same day he also contacted Michael Gove, saying: "I know you are manically busy – and doing a great job, by the way (this is bloody hard and I think the team is coping extremely well. But do you have a moment for a word? I am on this number and v free. All good wishes Dc."
After arranging to talk with the chancellor, Mr Cameron texted Mr Gove: "Am now speaking to Rishi first thing tomorrow. If I am still stuck, can I call you then?"
After the discussion he wrote to Sir Tom, telling him that his ultimate ask was for "one more high level chat" with him and that the chancellor had "agreed".
However, Mr Cameron messaged Mr Sunak again on 22 April to apologise for "troubling you again" and asking if he could help with regards to the CCCF and if he could "give it another nudge over the finish line".
The two continued to stay in contact, with Mr Cameron asking the chancellor on 18 May "for the last time, I promise" to instruct senior Treasury official Charles Roxburgh to look into the matter again.
Another message from Mr Cameron to Sir Tom, sent last March, read: "I am riding to the rescue with Supply Chain Finance with my friend Lex Greensill – my new job [REDACTED]. See you with Rishi’s for an elbow bump or foot tap. Love Dc."
The correspondence released by the Treasury committee shows that between March and June 2020, Mr Cameron sent:
• 14 text messages to Tom Scholar, permanent secretary of the Treasury
• Eight WhatsApp messages and two phone calls to Chancellor Rishi Sunak
• Five texts to economic secretary to the Treasury John Glen
• One call, one text message and one email to financial secretary to the Treasury Jesse Norman
• Two text messages to Michael Gove
• Two WhatsApp messages to Richard Sharp, an aide to Rishi Sunak
• Three text messages, two emails and two phone calls to Sheridan Westlake
• Four emails, one text messages and one call to Sir Jon Cunliffe, deputy governor of the Bank of England
• One WhatsApp message to vaccines minister Nadhim Zahawi.