Act now on sleaze crisis or lose red wall votes, Boris Johnson warned

Boris Johnson will lose the trust of former Labour voters who helped put him in Downing Street unless he tackles the burgeoning sleaze crisis now threatening to engulf his government and the Whitehall machine, a leading Tory says today.

The warning from Sir Bernard Jenkin, chair of the powerful Commons liaison committee, is evidence of mounting concern in Conservative ranks about the potential electoral damage to the Tory party, particularly in so called “red wall” seats, from any further revelations like the David Cameron lobbying scandal.

Related: The line between public service and private gain is shamefully blurred

Details of Cameron’s attempts to lobby Tory ministers on behalf of the Australian financier Lex Greensill have been followed in recent days by news that supposedly independent civil servants have been allowed to take on concurrent jobs in the private sector.

The Labour party is now raising further questions about the financial interests of senior Conservatives and of advisers to the government, including those of the health secretary, Matt Hancock, Johnson’s own adviser on civil service reform, Francis Maude, and the prime minister’s deputy chief of staff, Simone Finn.

Writing in today’s Observer, Jenkin calls for reform and an end to a situation in which the lines between public and private interests are unclear.

“There is nothing wrong with a private citizen wanting to make money, but we have a system which has allowed the lines between public service and private gain to become blurred,” he says, describing the current situation as “shameful” and “utterly corrosive of public trust in government”.

In a clear warning to the prime minister and a swipe at Cameron and his chancellor, George Osborne, Jenkin adds: “This should matter to Boris Johnson. He does not need to pretend to be a saint, but his ‘red wall’ voters, who gave him his majority, will start to dismiss him unless he can show he is more open, more transparent and very different from the out-of-touch elite he defeated in the 2016 referendum and ousted from government.”

Labour is demanding answers to a series of questions regarding Johnson’s own team ahead of several imminent parliamentary inquiries in the Greensill-Cameron saga.

On Saturday night the shadow Cabinet Office minister, Rachel Reeves, demanded to know what checks had been made before Lord Maude was appointed to an unpaid role advising Johnson on Whitehall reform when he runs a company – Francis Maude Associates (FMA) – that advises foreign governments on how to be more efficient.

She believes Maude may greatly increase the marketability of his company by telling potential clients of his role inside No 10 and of his contacts there. Reeves is also asking a similar question about Lady Finn, who is a friend of Maude and has a 35% share in his company.

“We need urgent clarification from the government on these roles and complete transparency on what due diligence was done, to avoid any potential perceived or real conflicts of interest,” Reeves said.

Downing Street insists that there is no conflict of interest in either case and that no rules have been broken.

In a new twist on Saturday night the Cabinet Office suggested Maude had now completed his advisory role. “Lord Maude has conducted a short review on how to increase the efficiency and effectiveness of government functions and controls,” it said.

The Guardian has also revealed that the man who was appointed by Boris Johnson to rule over the Greensill lobbying scandal in an independent inquiry is on the board of a private bank that has close ties with the Conservative party. Finn sat on its board until recently.

The shadow health secretary, Jonathan Ashworth, on Saturday night raised concerns about Hancock’s involvement in a family firm, in which he has a 15% holding, which uses the NHS logo on its website.

Ashworth said there was a risk of a conflict of interest. Hancock says there is no conflict and no rules have been broken.

Meg Hillier, who chairs the powerful public accounts committee, said Treasury officials seeing MPs this week needed to explain why Greensill Capital appeared to have been given a special hearing as it attempted to gain access to government schemes. Several meetings were held with Lex Greensill before it was rejected from one scheme. However, the British Business Bank later granted it access to another government-backed loans scheme. “Greensill was one of only two non-regulated banks that got money through one of the schemes,” said Hillier.

“The question is why. The Covid crisis does not mean we should lighten up on transparency because it’s difficult. Actually, we should be more transparent at times like this.

“We’ve had sofa politics, which was criticised for being too informal. Now we’ve got WhatsApp politics. In terms of the Treasury’s handling of Greensill, they need to be really clear about why they kept meeting someone if the answer was always going to be ‘no’.”

The Observer has been told that Greensill will be prepared to attend inquiries into his role in the Cameron government and his subsequent links with the former prime minister.

A spokesperson for the Greensill family said: “Lex would be delighted to assist the UK government in its inquiries into these issues and to set the record straight.