David Cameron is to face a grilling by MPs over his lobbying activities for collapsed finance firm Greensill Capital.

Questions have been mounting over the former prime minister’s efforts to secure access for the finance company, which collapsed in March putting thousands of UK steelmaking jobs at risk.

Ahead of the back-to-back hearings by the Commons Treasury and Public Accounts committees, the PA news agency looks at how the controversy unfolded and what happens next.

– What is the Greensill row about?

Labour led calls for an inquiry after it emerged that Mr Cameron had privately lobbied ministers, including Chancellor Rishi Sunak, to win access to an emergency coronavirus loan scheme for his employer, Lex Greensill.

Allegations also surfaced that Mr Greensill, an Australian financier, was given privileged access to Whitehall departments when Mr Cameron was in No 10.

– What was David Cameron’s involvement?

Mr Cameron sent a number of texts to Mr Sunak’s private phone asking for support for Greensill, which later collapsed into administration, through the Government’s Covid Corporate Financing Facility (CCFF).

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 Conservative leader also emailed a senior Downing Street adviser pressing for a rethink on Mr Greensill’s application for access to emergency funding.

– Who else did he contact?

Correspondence published by the Commons Treasury Committee on Tuesday shows that the former prime minister bombarded ministers and Government officials with text messages.

Mr Cameron provided their inquiry with texts he had sent during his work as an adviser to Greensill, which revealed that he had also contacted senior Cabinet minister Michael Gove and vaccines minister Nadhim Zahawi.

– What has Mr Cameron said about the row?

Mr Cameron has insisted that, in his representations to Government, he did not break any codes of conduct or lobbying rules.

But he did acknowledge that he should have communicated with the Government “through only the most formal of channels”, rather than texts to Mr Sunak, and said he accepts there are “important lessons to be learnt”.

Mr Cameron said some of the reported allegations “are not correct”, as he challenged what he called a “false impression” that Mr Greensill was a key member of his team while prime minister.

– And what about Mr Greensill?

Appearing before the Commons Treasury Committee on Tuesday as part of their inquiry, Mr Greensill apologised and said he took full responsibility for the collapse of his financial group.

He told MPs: “It’s deeply regrettable that we were let down by our leading insurer, whose actions assured Greensill’s collapse, and indeed some of our biggest customers.

“To all of those affected by this, I am truly sorry.”

– Are jobs on the line?

Greensill was the main financial backer of Liberty Steel, and its collapse has left the firm, which employs about 5,000 workers at a number of sites across the UK, facing an uncertain future.

– Isn’t there an independent review into this?

A series of investigations is under way into the role the former prime minister played in securing Whitehall access for the company and Mr Greensill.

Among them is a review, commissioned by the Cabinet Office on behalf of Prime Minister Boris Johnson, which will examine how Government contracts were secured by the company and the actions of Mr Cameron.

– Who is leading the review?

Nigel Boardman, who is a non-executive board member of the Department for Business, Energy and Industrial Strategy, and chairman of the Audit and Risk Assurance Committee.

The lawyer has previously conducted a review of Cabinet Office procurement processes, according to Downing Street.

– What has the watchdog said?

The Registrar of Consultant Lobbyists cleared Mr Cameron of breaking lobbying rules because, as an employee of Greensill, he was not required to declare himself on the register.