The extent of David Cameron’s intense lobbying efforts for Greensill Capital during the coronavirus pandemic has been revealed by the publication of text messages he sent Chancellor Rishi Sunak and senior Cabinet minister Michael Gove.

The Conservative former prime minister and his office staff sent ministers and officials around 73 emails, texts and WhatsApp messages relating to the now-collapsed firm in less than four months, it emerged on Tuesday.

Mr Cameron also sent messages to vaccines minister Nadhim Zahawi during the Covid-19 crisis as he sought to gain access for Greensill to Government-backed coronavirus loans, opposition to which he derided as “nuts” and “bonkers”.

MPs on the Commons Treasury Committee released correspondence they have received by the subjects of their inquiry into the financial firm’s failure, which jeopardised 5,000 steelmaking jobs in the UK.

It also emerged in the correspondence that the Financial Conduct Authority (FCA) is formally investigating the company, having received allegations relating to the firm’s collapse that were “potentially criminal in nature”.

Mr Cameron provided the inquiry with messages he sent Government officials and ministers during his work as an adviser to Greensill.

One text message to Mr Gove on April 3 last year acknowledged the minister is “manically busy”, adding: “But do you have a moment for a word? I am on this number and v free. All good wishes Dc.”

“Thank you! Will call!” the Cabinet Office minister replied, according to a separately-published response to a Freedom of Information request.

On the same day, Mr Cameron sent a separate message to the Chancellor asking for a “very quick word” on the Treasury refusal to grant access to the Covid Corporate Financing Facility (CCFF).

“HMT are refusing to extend CCFF to include supply chain finance, which is nuts as it pumps billions of cheap credit into SMEs,” Mr Cameron wrote.

“Think there is a simple misunderstanding that I can explain.”

After arranging a discussion with Mr Sunak, the former prime minister messaged Mr Gove: “Am now speaking to Rishi first thing tomorrow. If I am still stuck, can I call you then?”

“Of course! Any time,” Mr Gove responded.

Following the talks, Mr Cameron wrote to Treasury permanent secretary Sir Tom Scholar saying that his ultimate ask was for “one more high-level chat” with Sir Tom, adding that the Chancellor had “agreed”.

But on April 22 the former Conservative leader texted Mr Sunak again to apologise “for troubling you again” but asking if he could help on CCCF and if he could “give it another nudge over the finish line”.

Communications still continued, however, and he asked “for the last time, I promise” for Mr Sunak to instruct senior Treasury official Charles Roxburgh for another look at the matter.

Another message to Sir Tom, in March last year, read: “See you with Rishi’s for an elbow bump or foot tap. Love Dc.”

Other recipients of Mr Cameron’s texts include Boris Johnson’s senior adviser Sheridan Westlake, Treasury ministers Jesse Norman and John Glen, and deputy Bank of England governor Sir Jon Cunliffe.

He also called Health Secretary Matt Hancock, according to records of the exchanges taking place between March 5 and June 26 last year.

The timeline of his contacts submitted by the former prime minister ahead of his appearance before the committee on Thursday also included 10 telephone calls or conference calls he was involved in, including one with Mr Sunak.

He also recorded 12 texts sent to Sir Tom and one call and six emails to Bank of England deputy governor Sir Jon.

The correspondence was released ahead of the collapsed firm’s boss, Lex Greensill, appearing before MPs on Tuesday afternoon.

He confirmed to the committee that Mr Cameron regularly attended Greensill Capital board meetings and received share options, saying they were less than 1% but declining to say how much less.

Nikhil Rathi, the chief executive of the FCA, said the regulator was investigating Greensill Capital UK (GCUK).

“We are also co-operating with counterparts in other UK enforcement and regulatory agencies, as well as authorities in a number of overseas jurisdictions,” Mr Rathi said.

“As the committee will be aware, a number of allegations have been made in the press regarding the circumstances of Greensill’s failure, some of which are potentially criminal in nature.

“There are, therefore, some aspects of the FCA’s interactions with Greensill entities that I am not able to disclose so as not to prejudice these ongoing investigations.”

Greensill was placed into administration in March, threatening thousands of UK jobs at Liberty Steel which was dependent on its finance.

In a letter to the committee, Mr Cameron said the “first time I became concerned that the company might be in serious financial difficulty was in December 2020” following a call from Mr Greensill.

“Up until that point, I firmly believed that Greensill was in good financial health,” the former Conservative leader added.