A fifth of Whitehall’s non-executive directors appointed to oversee the work of government departments have “significant political experience or party alignment”, according to new evidence that ministers are using the posts to bolster their own support.

It comes as demands grow for a complete overhaul of the appointment of Whitehall’s army of non-executive directors (Neds), who have come in for greater scrutiny since Matt Hancock, the former health secretary, was found to have appointed his aide and lover, Gina Coladangelo, to the role at the Department of Health and Social Care last year.

Coladangelo has since left the post following the public exposure of their affair. However, Hancock’s decision to appoint her highlighted the fact that ministers across Whitehall have appointed figures known to be close to them personally. Neds are meant to scrutinise both ministers and their department as part of the role, but there are concerns that they are increasingly being used to bolster ministers and effectively act as special advisers.

About 20% of the 94 non-executive directors currently in post have political experience or allegiances, according to a new analysis by the Institute for Government (IfG) thinktank. It called for a complete overhaul of how they are appointed. Under current rules, their appointments are not regulated in the same way as other senior Whitehall posts, “making it impossible to know whether candidates are genuinely being appointed on merit, or if advantage is being given on grounds of political affiliation”.

Of the 19 Neds identified as having significant political experience or ties, the analysis found 15 exclusively supported the Conservatives, while two – Tory donor Ben Goldsmith and former Conservative and Ukip MP Douglas Carswell – have campaigned for the Conservatives alongside other parties, and one, Gisela Stuart, worked with Conservative politicians on the Leave campaign. 

Rates of work-related stress, depression and anxiety among civil servants has risen drastically in the past year to the highest level for decades, amid warnings that Whitehall will reach “breaking point”.

The proportion of civil servants who say they are experiencing stress has increased by 45%, according to official data. Increasing workloads, looming deadlines, departures of senior staff and the pressures around delivering Brexit are all being blamed for the spike.

It appears to be the highest rate recorded for any industry since the Health and Safety Executive began collecting these statistics 20 years ago. About 3,230 cases of stress, depression and anxiety per 100,000 workers were recorded for the sector and related jobs, the highest rate of any sector in the UK and around 77% higher than the all-industry average.

Unions blamed the figures on increasing workloads, years of pay restraint and the added pressures created by Brexit and political gridlock. Mike Clancy, general secretary of the Prospect union, said: “No other industry has experienced anything like this annual jump, and it is impossible to escape the conclusion that it is because of the sheer level of pressure being heaped on civil servants as a result of Brexit.

“No government in peace time has ever been as reliant on its civil service, keeping the country running and preparing for Brexit, while parliament remains effectively deadlocked. Pay is still lagging behind the private sector, departmental cuts continue to bite, and senior politicians never seem to miss an opportunity to attack civil servants – it’s no wonder they are feeling the strain.

‘The government urgently needs to address this problem or it will soon discover that even our fantastic civil service has a breaking point.”

The number of people in the public sector’s largest pension schemes retiring on incomes of more than £100,000 has more than tripled in the past seven years, according to figures obtained by a charity promoting intergenerational fairness.

Pensions schemes covering the NHS, the civil service and the teaching profession were paying six-figure incomes last year to 375 retirees, up from 117 in 2010. 

Those in receipt of pensions higher than the UK’s average annual salary of about £28,600 also increased by 46% – up from 78,000 in 2010/11 to 115,000 in 2017/18.

The Intergenerational Foundation said the figures, which it obtained through freedom of information requests, illustrated a growing divide between the generations.

Angus Hanton, the co-founder of IF, said the figures excluded the state pension, which adds another £8,767 to the incomes of new retirees and would likely push the pensions of thousands more public sector workers above the average wage.

He said successive governments had sought to protect those close to retirement at the expense of a younger generation whose pensions would be much less generous.

The government has stood down an army of 6,000 civil servants who had been preparing for a no-deal Brexit, at an estimated cost of £1.5bn.

The civil servants who had been seconded from elsewhere will now return to their normal duties, but there is no clear role for an estimated 4,500 new recruits after article 50 was extended until Halloween.

More than 16,000 civil servants in total have been working on Brexit.

The Labour party’s Hilary Benn said it was a “costly price” to pay for Theresa May’s belligerent insistence of keeping a no-deal on the table.

“It was important to plan for all contingencies, but this is the huge cost of the prime minister repeatedly saying: ‘My deal or no deal’ when she knew that leaving without a deal was not in the national interest. This is one example of how Brexit is proving to be very costly for our country,” said Benn, chair of the influential Brexit select committee.

The Cabinet Office made the decision to reverse the no-deal plans at a meeting on Thursday morning.

For most of last year, Whitehall escaped direct hits from resurgent populism, but this could be a year where public servants come under sustained attack. It is easy to imagine how this might happen. In 2017, any honeymoon will be well and truly over for prime minister Theresa May. Brexit draws closer. The difference by rhetoric and delivery will widen. Months will have passed since the referendum, yet everything will appear to be the same or worse. Who to blame? Those pesky Europeans? Well, of course. But they will bite back. How about going for those who can’t respond? Officials are a tempting target.

Whitehall will need to respond to this, but will find the going very hard. We are all wired to seek out information that supports the coherence of our worldview. The civil service’s worldview is compiled of data, evidence and the opinions of other learned folks. But if 2016 reminded us of anything, it’s that many people don’t make their decisions on that basis, however much one insists they should. A neat, logical chain of facts is only one form of argument. It was not one that performed well last year.

When it comes to making a case, the civil service is completely wedded to this logical framing of arguments. It provides the basis for every ministerial submission, every white paper, every business case. Civil servants are not allowed to appeal to rhetoric, emotion, beauty or pride. That is not their job. But narrow-mindedness presents a real problem. How can the civil service defend itself adequately if it is unable to put forward arguments that resonate with people who intuit things in a different way to civil servants?