David Cameron will give evidence to MPs over the Greensill lobbying row, the former PM’s spokesman said amid a raft of Whitehall revolving door revelations.

There are now expected to be four inquiries into failed financiers Greensill Capital and lobbying, following pressure from Labour to set up a committee of MPs specifically to look into it.

Boris Johnson ’s own probe will be led by lawyer Nigel Boardman, who is a non-executive director at the Business department, but will “pause” his government position while he undertakes the review. It’s expected to report back in June.

The Treasury Committee is set to specifically look into Greensill, while the Public Administration and Constitutional Affairs Committee and the Committee on Standards are expected to look into the broader issues around Lobbying.

Mr Cameron’s spokesman said the ex-PM will respond “positively” to any request to give evidence to any of the inquiries.

The spokesman said Mr Cameron was keen that "lessons are learned".

Mr Cameron is said to be keen that "lessons are learned"
Mr Cameron is said to be keen that "lessons are learned"

"David Cameron will respond positively to all such requests when the terms of reference of each inquiry are made clear and any invitations to provide evidence are received," the spokesman said.

"While he was an adviser to the business and not a board director, he is keen to ensure that lessons from it going into administration are learned."

Last night, Whitehall departments were ordered to declare any senior officials who held paid jobs outside of government.

Simon Case, the Cabinet Secretary, said there was "acute concern" at the top of the service about the lobbying row.

It comes after it was revealed former government chief commercial officer Bill Crothers worked as a part-time director at Greensill Capital while still in Whitehall.

In a letter to permanent secretaries, Mr Case said that while there was a role in government for people with outside expertise, it was essential for the "integrity and impartiality" of the civil service to be maintained.

In particular, there had to be "transparency and full proper management" of any outside interests, and those that conflicted with officials' obligations under the Civil Service Code are not permitted.

Mr Case wrote: "If you come across any instances of senior civil servants holding remunerated positions or other interests outside government which might conflict with their obligations under the code please bring them to mine and (Cabinet Office director general of propriety and ethics) Darren Tierney's attention immediately and, at the latest, by the end of this week."

Mr Case said it was essential for departments to "engage fully" with the review commissioned by Boris Johnson, being carried out by legal expert Nigel Boardman.

"If, as Nigel Boardman completes his review, he identifies areas where we as a civil service have made mistakes, it is important that we are honest about these and learn from them," he added.