On what he called “a painful day”, he listened to one Labour MP telling him he had “demeaned yourself and your position” by championing a “fraudulent enterprise”.
The former Prime Minister also clashed with Treasury Select Committee chair Mel Stride who pressed him to disclose his earnings. Mr Cameron said that was “a private matter”.
In fiery exchange Labour member Siobhain McDonagh demanded: “Do you not feel you have demeaned yourself and your position by What’s Apping your way around Whitehall, on the back of a fraudulent enterprise, based on selling bonds of high risk debt to unsuspecting investors?”
Mr Cameron replied: “My view is that what I did was I made a choice to work for a business which I hoped would be a UK FinTech success story and many people believe that.
“I wanted to help that company grow and expand. And what I did at the time of economic crisis was put to the government what I genuinely believed to be a good idea how to get money into the hands of small businesses and get their bills paid early.”
She said he had painted Mr Greensill “as a reincarnation of the late mother Teresa” and alleged: “We now know that 90 per cent of Greensill’s business was lending against transactions that have never happened, may never happen, and with companies that don’t even know that they are involved, and then selling it on at low risk. Mr Cameron, do you still believe that that business model was a good one?”
Mr Cameron responded, in a mild tone, that the supply chain finance developed by Greensill was “a good idea” used by many companies.
Ms McDonagh called on him to admit his lobbying of the NHS “wasn’t for its health, but for the health of Greensill’s balance sheet”.
Mr Cameron insisted: “I wouldn’t accept that for a second.”
He repeatedly stressed that he joined the company because he believed in its products, which included an app allowing NHS staff to be paid earlier.
The two-hour hearing followed disclosures that Mr Cameron sent over 60 private messages to ministers including Rishi Sunak and Michael Gove and top Whitehall officials when he was seeking an emergency loan from the Government for Greensill.
Former Labour minister Angela Eagle said she had read Mr Cameron’s messages, adding: “They are more like stalking than lobbying.
“Looking back, are you not at least a little bit embarrassed about the way that you behaved?”
Mr Cameron responded: “As I said, it was a particularly acute time in the British economy.
“The Government was introducing plans to try and help businesses. We thought we had a good idea.
“I was keen to get it in front of Government but as I’ve said, there are lessons to learn and lessons for me to learn and in future the single, formal email or formal letter would be appropriate. “
The hearing began with the former Prime Minster making an opening statement in which he told members: “This is a painful day for me: coming back to a place that I love and respect so much, but in these current circumstances.
“I have had plenty of time to reflect on what has happened to bring me to this place.
“I welcome this review, and I believe there are important lessons to be learnt.”
Among those lessons, he said, was that ex-premiers were different to other retired politicians. “I completely accept that former prime ministers are in a different position to others because of the office we held and the influence that continues to brig,” he adds. “We need to think differently and act differently.”
“I accept there is a strong argument that having a former prime minister engage on behalf of any commercial interest… can be open to misinterpretation.”
He made several proposals for improved rules, including that there should be a longer period than the current two years from leaving office before an ex-PM can take up paid lobbying.
After that, things became more heated. Mr Cameron clashed with Treasury Committee chairman Mel Stride by refusing to spell out what he earned from his role or stood to make in shares.
Mr Stride challenged him about his texts, suggesting: “Your opportunity to make a large amount of money was under threat… your fear of missing out led you to conduct this barrage of texts.”
Mr Cameron replied firmly: “That is not what I felt at the time and it is not what motivated me.”
He added: “I would never put forward something I did not believe was in the public good.”
Earlier he dismissed media claims that he expected to earn £60 million as “absurd”.
But Mr Stride said it made a difference whether he expected to make a small sum or a large sum. Mr Cameron confirmed he had a “big economic interest” in the company, thanks to shares and a salary that was bigger than he was paid as Prime Minister.
He said he saw the company as acting in the public good and had no idea it was on the brink of collapse. “The motivation for contacting government was that I thought we had a really good idea for extending credit to thousands of businesses.”
Mr Cameron confirmed he had a “big economic interest” in the company but said he acted for Greensill Capital because he was “excited” about its flagship financial product, an app that allowed NHS staff to take their salaries earlier.
Conceding that his 60-plus messages to ministers and officials looked bad, Mr Cameron said; “Looking back, … a single letter or email would be more appropriate. But we were in very different circumstances when Covid happened.”
Conservative MP Harriett Baldwin quizzed Mr Cameron over why he signed a text message to Treasury top mandarin Sir Tom Scholar “Love DC”.
“Can you just help the committee understand in particular why you used that to him, do you have a closer or wider personal relationship outside the formal one that you have just described,” she asked.
The ex-PM responded: “I think I have seen him perhaps once or twice since leaving office.
“Anyone I know even at all well I tend to sign off text messages with ‘Love DC’..I don’t know why, I just do.
“My children tell me that you don’t need to sign off text messages at all, and it’s very old-fashioned and odd to do so, but anyway that is what I do.”
Mr Cameron earlier told the committee that Sir Tom had been his No10 “sherpa” for G7 and G20 meetings, which means he helped preparations for such summits, as well as assisting with work ahead of European Council meetings.
He stressed that he had been urging people in Government to look at Greensill’s proposals and talk to the company in the “full knowledge” that any meeting subsequently held would be “transparently reported”.
He added: “So, the idea that there was anything sort of behind-the-hand or surreptitious trying to be attempted is nonsense.”
Asked again about his earnings by former minister Labour’s Angela Eagle, he said Mr Greensill had not been asked the same question and it was “irrelevant”.