Boris Johnson has commissioned a wide-ranging independent review into Greensill Capital, the collapsed financial firm for which David Cameron lobbied ministers.

Downing Street announced that lawyer Nigel Boardman is due to lead the probe, which will examine how Government contracts were secured by the company and the actions of the former prime minister.

Mr Cameron accepted that he should have communicated with the Government “through only the most formal of channels” rather than text messages to Chancellor Rishi Sunak as he acknowledged mis-steps over the controversy.

Breaking his weeks of silence, the former Conservative prime minister said in a statement to the PA news agency that, having “reflected on this at length”, he accepts there are “important lessons to be learnt”.

The Cabinet Office is commissioning an independent review on behalf of the Prime Minister, to establish the development and use of supply chain finance and associated activities in Government, and the role Greensill played in those

Downing Street said Mr Johnson had called for the independent review to be launched into Greensill, which collapsed into administration in March, due to “significant interest” in the matter.

The Prime Minister’s official spokesman told a Westminster briefing: “The Cabinet Office is commissioning an independent review on behalf of the Prime Minister, to establish the development and use of supply chain finance and associated activities in Government, and the role Greensill played in those.

“As you know, there is significant interest in this matter, so the Prime Minister has called for the review to ensure Government is completely transparent about such activities and that the public can see for themselves if good value was secured for taxpayers’ money.

“This independent review will also look at how contracts were secured and how business representatives engaged with Government.”

Leading the inquiry will be legal expert Mr Boardman, a non-executive board member of the Department for Business, Energy and Industrial Strategy who has previously conducted a review of Cabinet Office procurement processes.

Downing Street said Mr Boardman will have “access to the documents that he needs” in his probe, which the Prime Minister wants to be completed “thoroughly” and “promptly”, according to his spokesman.

A spokesman for Mr Cameron said: “We welcome this inquiry and will be glad to take part.”

But Labour said the review, announced on Monday, risks kicking the issue into the “long grass”.

Shadow chancellor of the Duchy of Lancaster Rachel Reeves said: “This has all the hallmarks of another cover-up by the Conservatives.

“Just as with the inquiry into Priti Patel’s alleged bullying, this is another Conservative Government attempt to push bad behaviour into the long grass and hope the British public forgets.

“We need answers on Greensill now – that means key players in this cronyism scandal like David Cameron, Rishi Sunak and Matt Hancock appearing openly in front of Parliament as soon as possible to answer questions.”

The Opposition will seek to maintain pressure on the Government over the issue on Tuesday when a minister will be forced to respond to an urgent question from shadow chancellor Anneliese Dodds on the issue.

The Sun reported that ministers and special advisers across Whitehall have been ordered to declare any contacts with Mr Cameron.

Mr Cameron’s predecessor, Gordon Brown, called for tougher rules to prevent former prime ministers lobbying within Government, claiming it “brings public service into disrepute”.

Former Labour leader Mr Brown said that former prime ministers should not be “lobbying for commercial purposes” and suggested legislation banning the practice for five years if existing rules cannot be made to work.

“I can’t comment on the individual detail of this but for me there are principles about public service – it cannot ever become a platform for private gain,” the former prime minister told BBC Radio 4’s Today programme.

“Ministers must never be lobbying, former ministers, prime ministers, must never be lobbying for commercial purposes. Current ministers should not be entertaining such lobbying.

“If we can’t succeed in achieving this stopping by the sort of flexibility of the rules, we are going to have to pass laws to make sure that at least for, say, five years, no serving or former prime minister or minister is ever lobbying for any commercial purpose within government.

“It simply brings public service into disrepute.”

The row surfaced when it emerged that Mr Cameron privately lobbied ministers, including with texts to Mr Sunak, to win access to an emergency coronavirus loan scheme for his employer, financier Lex Greensill.

It was later reported that Mr Cameron had arranged a “private drink” between Health Secretary Matt Hancock and Mr Greensill to discuss a payment scheme later rolled out in the NHS.

The former prime minister – who was in Downing Street from 2010 to 2016 – said in a statement: “In my representations to Government, I was breaking no codes of conduct and no Government rules.”

He said that “ultimately” the outcome of his efforts to get Greensill’s proposals included in the Government’s Covid Corporate Financing Facility (CCFF) was that “they were not taken up”.

“So I complied with the rules and my interventions did not lead to a change in the Government’s approach to the CCFF,” he added.

“However, I have reflected on this at length. There are important lessons to be learnt.

“As a former prime minister, I accept that communications with Government need to be done through only the most formal of channels, so there can be no room for misinterpretation.”

Questions had been mounting over his efforts to secure access for the finance company, which later collapsed, putting thousands of UK steelmaking jobs at risk because the firm was the main backer for Liberty Steel.

The Chancellor responded to the numerous private texts from Mr Cameron by saying on April 23 last year that he had “pushed” officials to consider plans that could have helped Greensill.

Mr Cameron also described the decision to exclude his employer’s firm from the multibillion-pound scheme as “nuts” in an email to a senior adviser to Mr Johnson and pressed for the Chancellor to reconsider.

“What we need is for Rishi (Sunak) to have a good look at this and ask officials to find a way of making it work,” Mr Cameron emailed on April 3 last year.