Once a week the most important people in the country that you’ve never heard of assemble in an office next door to Downing Street.

They are the heads or deputies of every Whitehall department, and sometimes there are up to 38 of them crowded into a wood-panelled room with a conference table and squashy sofas for what is called the ‘Wednesday Morning Colleagues’ meeting.

This innocuous-sounding gathering is presided over by one Simon Case who, as Cabinet Secretary, is the most senior civil servant in the land. At 44, Case is not just one of the youngest in this room, he is also one of the most inexperienced.

One senior minister, who has sat around countless official tables with the bearded bureaucrat, says: ‘He is incredibly conscious of the fact that he is more junior than most of the permanent secretaries who take their orders from him.’

For a man of towering ambition, this rankles. His sense of insecurity is brutally underlined by the fact that there are often up to 12 knights and dames of the realm at these meetings.

At 44, Simon Case (pictured) is not just one of the youngest in this room, he is also one of the most inexperienced

For a man of towering ambition, this rankles. His sense of insecurity is brutally underlined by the fact that there are often up to 12 knights and dames of the realm at these meetings. Pictured: Simon Case (centre) addresses a Cabinet meeting at Downing Street in 2022

Case’s lack of a knighthood came under intense scrutiny this week — as did his integrity — thanks to a series of explosive and frankly juvenile contributions to the Covid Inquiry.

Though he has yet to appear in person at the London hearings, text messages and WhatsApps he sent during the pandemic have been shared. In one he describes those around then Prime Minister Boris Johnson’s No 10 operation as ‘poisonous’ and ‘mad’, adding: ‘I’ve never seen a bunch of people less well-equipped to run a country.’

In another, to his predecessor Lord Sedwill, he declares: ‘It is like taming wild animals. Nothing in my past experience has prepared me for this madness.

‘The PM and the people he chooses to surround himself with are basically feral . . .’ The two men shared a particularly egregious exchange about former Health Secretary Matt Hancock, whom Lord Sedwill observed was ‘so far up BJ’s [Boris Johnson’s] a*** his ankles are brown’. This, the ex-mandarin limply suggested during his evidence earlier this week, was merely ‘gallows humour’.

For now, Case, who is on leave from his £205,000-a-year post for medical reasons, has not confirmed this observation.

Within months of accepting the job, which came after a stint as Prince William’s private secretary, Case was confidently telling the Prime Minister that senior officials did not want to work in Downing Street ‘because of the toxic reputation of his operation’.

To Lord Sedwill he had a more nuanced but no less critical observation: ‘At this rate I will struggle to last six months. These people are so mad. Not poisonous towards me (yet) but they are just madly self-defeating.’ Lord Sedwill warned him, ‘Watch yourself’, adding: ‘It is hard to ask people to march to the sound of gunfire if they’re shot in the back.’

Naturally there is no shortage of private glee among Tory figures at this turn of events. Case likes to remind people that he does, actually, have a title: he is Dr Case thanks to his postgraduate degree under the eminent constitutionalist and historian Lord (Peter) Hennessy.

Indeed, in one exchange he despaired about Boris’s WhatsApps because, he told him, they would almost certainly become part of a future inquiry. Advice, it seems, that he did not take himself. Pictured: Boris Johnson and Carrie Symonds watch the 2019 Election results

In a series of damning messages he described the Government, of which he was the most senior and impartial servant, as a ‘terrible, tragic joke’

Perhaps his lofty confidence was the result of being praised too highly too soon in life — he has held a series of senior positions but, curiously, never for very long. Or perhaps, like so many who make their way into influential roles, he felt his status was impregnable.

Nevertheless, critics suggest his remarks were not just childish but also revealed a complicity in the apparent shambles at No 10. As one figure told us: ‘He has fallen foul of the basic civil service rule to never put in writing anything that might subsequently be discoverable and produced against you.’

Indeed, in one exchange he despaired about Boris’s WhatsApps because, he told him, they would almost certainly become part of a future inquiry. Advice, it seems, that he did not take himself.

In a series of damning messages he described the Government, of which he was the most senior and impartial servant, as a ‘terrible, tragic joke’.

Criticising No 10’s handling of the pandemic, he suggested Mr Johnson’s now-wife Carrie was ‘the real person in charge’.

The inquiry was shown what were said to be messages between Case and Boris’s director of communications, Lee Cain, in the autumn of 2020. Asked by Cain what issues were being discussed, Case replied: ‘Whatever Carrie cares about, I guess.’

He added: ‘I was always told that Dom [No 10 aide Dominic Cummings] was the secret PM. How wrong they are. I look forward to telling Select Committee tomorrow, “Oh, f*** no, don’t worry about Dom, the real person in charge is Carrie”.’

These remarks are not just unpleasant but they go to the heart of the kind of civil servant Case saw himself as. Haughty and imperious spring to mind.

Father-of-three Case, a competitive rower at Cambridge University, where he met his wife Liz, is a member of the Garrick Club where he likes to sit at its famous long table guaranteeing he will be spotted by other diners. Pictured: Boris Johnson, accompanied by Simon Case in 2020

The two men shared a particularly egregious exchange about former Health Secretary Matt Hancock, whom Lord Sedwill observed was ‘so far up BJ’s [Boris Johnson’s] a*** his ankles are brown’

‘A very un-civil servant,’ as one of Mr Johnson’s Cabinet described him to us. Yet, as Cabinet Secretary, Case is privy to all manner of confidential and secret information and a man from whom one would expect the highest level of discretion, certainly in terms of what he would put in writing.

And then there is what he says. The idea that the Prime Minister’s wife was somehow running Downing Street was a criticism that was frequently hurled as a slur by opponents during lockdown and was usually dismissed as a misogynistic, Lady Macbeth-type of caricature.

To see this idea repeated at the time by the Cabinet Secretary and the No 10 director of communications is astonishing. But then Case didn’t mince his words about Boris’s shortcomings either.

‘He cannot lead,’ he wrote in a WhatsApp thread at the height of the pandemic, ‘and we cannot support him in leading with this approach.

‘The team captain cannot change the call on the big plays every day. Government isn’t actually that hard but this guy is really making it impossible . . .’

In messages to Cummings, Case complained that Boris ‘changes strategic direction every day’ and said he was ‘at the end of [his] tether’. But then Case’s hand had already been revealed when, earlier this year, a newspaper published a tranche of WhatsApp messages involving Matt Hancock.

In a conversation from October 2020, Case was quoted as describing Mr Johnson as a ‘nationally distrusted figure’ and warned that the public were unlikely to follow rules around isolation if they were set out by him.

A few months later, in February 2021, Case mocked holidaymakers who were being forced to go into quarantine. ‘Any idea how many people we locked up in hotels yesterday?’ he asked the Health Secretary. When Hancock explained that 149 were in quarantine hotels, Case responded contemptuously: ‘Hilarious.’

Criticising No 10’s handling of the pandemic, he suggested Mr Johnson’s (right) now-wife Carrie (left) was ‘the real person in charge’

Case’s supporters would point out that all this occurred when he was having to manage the national response to the greatest peacetime crisis to hit the country for a generation. But his detractors insist this does not absolve him of blunders that occurred on his watch.

He was photographed at a birthday event for Mr Johnson in the Cabinet Room when lockdown restrictions were in place in June 2020. Both Boris and then- Chancellor Rishi Sunak were fined for attending. The decision of the police not to fine Case baffled many colleagues — as did his subsequent refusal to resign.

It meant he also had to recuse himself from chairing the subsequent inquiry into Partygate.

The first real criticism of Case came during the row over who paid for Mr Johnson’s Downing Street flat renovations. Case was accused of trying to ‘smooth over the cracks’ by overseeing the fallout from the refurbishment.

There was a disastrous appearance before the Commons Public Administration and Constitutional Affairs Committee in which he was admonished for a lack of preparation. Case was asked three times if the bill for the original refurbishment of the PM’s Downing Street flat had been paid for with private donations. Each time Case prevaricated, replying that he was conducting a review.

His response provoked the committee’s Tory chairman William Wragg to thunder: ‘Mr Case, you’ve known you’ve been coming [here] for weeks. I’m surprised you did not come here better furnished with answers.’

In more recent times, questions about his judgment were raised over his apparent failure to warn Mr Sunak — by now Prime Minister — about an official investigation into former Chancellor Nadhim Zahawi’s tax affairs.

Zahawi concluded a £5 million settlement with the tax authority in September 2022 while he was at No 11 before going on to become Tory chairman. In January, Zahawi was sacked by Mr Sunak after he was found to have breached the ministerial code by failing to declare the HMRC probe.

There was a disastrous appearance before the Commons Public Administration and Constitutional Affairs Committee (pictured) in which he was admonished for a lack of preparation

Case was also at the centre of the controversy which led to the resignation this year of banker Richard Sharp as chairman of the BBC over his role in a six-figure loan guarantee to Mr Johnson.

While he was applying to be BBC chairman, Sharp put a business acquaintance, Sam Blyth — who happened to be a distant cousin of Boris Johnson — in touch with the then Prime Minister, with a view to guaranteeing the loan.

But a memo sent by Case to Mr Johnson on December 22, 2020, which was later leaked, said: ‘Given the imminent announcement of Richard Sharp as the new BBC chair, it is important you no longer ask his advice about your personal financial matters.’ Sharp resigned in April after being found to have breached public appointment rules for failing to declare a connection to the secret £800,000 loan.

But for many Whitehall colleagues, Case’s most serious misdemeanour was a failure to intervene over the sacking last September of Tom Scholar, the top Treasury civil servant. He was fired without warning by new PM Liz Truss and her Chancellor Kwasi Kwarteng in their very first week in Downing Street.

Case was criticised by senior figures for his apparent acquiescence in the affair. Sir David Normington, former head of the Home Office, accused him of ‘failing to stand up for the values of the Civil Service’.

Scholar’s dismissal left Case horribly exposed, according to ministers. For, despite a CV bulging with high-powered jobs including director of strategy at GCHQ, heading the quango working on Britain’s EU departure, and lead civil servant on the Irish border issue post-Brexit, Case remains the least experienced civil service chief in modern times, having never run a Whitehall department.

And, intriguingly, he never remained long in any previous post. His appointment to the top position at No 10, when he was just 41, was not greeted with high hopes. Certainly, his time at the royal household working for William and Kate, then Duke and Duchess of Cambridge, where he was known as the ‘master of circumvention’, should have been ample preparation for the skulduggery of Downing Street.

His two years at Kensington Palace encompassed the fallout from Megxit, and he was front and centre in the uproar that followed the incendiary claims that the Duchess of Sussex and Prince Harry had bullied staff.

The former pupil at fee-paying Bristol Grammar School started his Whitehall career as a junior in the Justice Department in 2006. Pictured: Case, left, with Boris Johnson, Rishi Sunak and Therese Coffey

It emerged that Case had been sent an email detailing the allegations that two junior members of staff had been subjected to bullying and that a third had had their confidence shattered. An aide was quoted as telling The Times newspaper that Harry and Meghan were ‘outrageous bullies’.

According to reports, Case suggested that the allegations should be passed to the Palace’s internal human resources department. Insiders suggested that this was Case sidestepping the issue.

Harry certainly never forgot his brushes with Case. In his memoir Spare, he refers to three royal advisers who he claims undermined him, hastening his and the Duchess’s exile from Britain.

They are identified as ‘the Bee’, ‘the Wasp’ and ‘the Fly’. Case was subsequently named as ‘the Fly’ whom, the Prince wrote, had ‘spent much of his career adjacent to and, indeed drawn to, s***. The offal of government and media and wormy entrails, he loved it, grew fat on it, rubbed his hands in glee over it’.

Case’s rise up the greasy civil service pole was helped in no small part by a Cabinet Secretary predecessor, the late Sir Jeremy Heywood — nicknamed ‘Sir Cover Up’ — who helped promote him. And that rise has certainly been rapid.

The former pupil at fee-paying Bristol Grammar School started his Whitehall career as a junior in the Justice Department in 2006.

And, like Heywood, Case has the ability to emerge unscathed from scandal. ‘The Teflon Cabinet Secretary’, is how one colleague describes the official, who is now on his third Prime Minister and who operates more as a courtier than a traditional, faceless mandarin.

Father-of-three Case, a competitive rower at Cambridge University, where he met his wife Liz, is a member of the Garrick Club where he likes to sit at its famous long table guaranteeing he will be spotted by other diners.

If persistent rumours are true he may have more time for clubbable lunches in future. Even before the WhatsApp brouhaha, his stock had fallen. Mr Sunak has broadened his circle of advisers across Whitehall, but especially from the Treasury, side-lining Case.

The knighthood will, surely, eventually come, but for now he might want to reflect on a framed aphorism that one of his predecessors displayed on his desk when he worked for Prince William’s mother at Kensington Palace. It read: ‘Say it with roses, say it with mink, but never, ever, say it in ink.’

Advice that would have served Simon Case well.