As we head towards the new year, striking workers are squaring up for a long battle with the government. Increasingly under the spotlight in these disputes are the nine independent review bodies that make recommendations on how much to pay 2.5 million staff across the public sector, from prison officers to teachers.

Ministers have refused to negotiate on pay, saying they must follow the official recommendations.

But the TUC leader, Paul Nowak, has said the pay review bodies were “in danger of being brought into disrepute”.

Speaking to the BBC’s Today programme on Thursday morning, he said: “The government is hiding behind the pay review bodies, refusing to negotiate on pay and refusing to reach a reasonable settlement with our public sector unions.”

Despite the intense debate, the committees whose members decide the incomes of millions of workers are not high-profile. So who sits on them, and how accountable are they?

Members of the pay review boards are not allowed to discuss their work and their voting records are kept under wraps. Their conclusions are agreed “collectively”, and there is little interrogation by parliament.

Unions have complained they can only make submissions to pay review bodies. Unlike the Low Pay Commission, which sets the level of the minimum wage and counts senior TUC official Kate Bell among its nine commissioners, unions are excluded from having representatives on the pay bodies themselves.

House of Commons select committees have no opportunity to quiz nominated members about their qualifications before they are appointed by the prime minister, as they can with Bank of England policymakers.

There is one former trade union official on the NHS pay review body (NHSPRB), Stephanie Marston. She previously worked for the Prospect union, which covers 100,000 professional workers in the civil service and private sector.

A spokesperson for Prospect said it had no contact with Marston, who quit her union job in 2017.

Unions also argue membership is heavily skewed towards retired senior management executives with little sympathy for the concerns of workers. Members are barred from talking about their role, so it is only possible to judge their sympathies based on their previous jobs and rare interviews.

The chair of the health pay review body is Philippa Hird, a former head of personnel at ITV and now a serial nonexecutive director. The 58-year-old studied politics, philosophy and economics (PPE) at Oxford University in the same year as Boris Johnson.

Like all other review body members, she serves a three-year renewable term. As chair, she is paid £350 a day, for preparation and attendance at 15 meetings a year. The fee for other members is £300 a day. In some years, there are more than 15 meetings.

Hird, who is in the last year of her second term, sits on several government boards, including the Strategic Command overhaul of the British armed forces. Last month, she was parachuted in as a member of the pay review board for top civil servants, judges and senior police officers.

Karen Mumford is a member of the review body who might be thought of as a friend of the worker in her role as a labour market economist and professor at York University.

However, she describes herself as “essentially a neoclassical labour economist” and counts the godfather of free market economics, Adam Smith, as among her principal influences.

Stephen Boyle is the other economist on the review body. He spent most of his working life as a highly paid finance industry executive, most recently as the chief economist at Royal Bank of Scotland.

Richard Cooper was a senior manager at BT who continues to be “a highly accomplished senior executive” at the Health Research Authority and the accountancy body, the ACCA.

Neville Hounsome and Anne Phillimore are longtime board-level personnel directors, while Patricia Gordon was a hospital trust chief executive for much of her career.

The armed forces have a pay review body (AFPRB), while the doctors and dentists’ remuneration body – the DDRB – covers nearly 250,000 hospital doctors, GPs and dentists.

Prison officers, who are not allowed to strike, have a separate pay review body and so do the police and school teachers. Lastly, the National Crime Agency has its own remuneration review body, the NCARRB.

The NHSPRB’s most recent report was three months late when it appeared in July covering the year 2022-23.

A three-year pay deal covering 2018, 2019 and 2020 for all NHS staff ended with the first meaningful assessment by the board in 2021, when a 3% pay offer was accepted by the government, breaching a public sector-wide freeze.

Tory MP Dan Poulter pointed to this hiatus when criticising the government’s current approach. He said given ministers had “chosen to ignore independent pay review body advice” for four years, it was “rather disingenuous for the government to now accept the recommendations because it is financially expedient for it to do so”.

The eight-strong body met 21 times in the year to July 2022 to compile a 165-page report, which set out recommendations for this year’s pay settlement.

The report recommended a minimum 4% for and up to 9.3% for low earners, saying it “delivers investment in staff pay that goes some way to reducing the risk that pay is a reason to leave NHS service”.

In its submission to the NHSPRB, the Treasury said inflation was expected to peak at about 4% in 2022, and that its was likely to return quickly to the Bank of England’s 2% target.

There were the usual caveats to the forecast, but it added that private sector employers appeared confident they could restrict average pay awards to 2.5% in the 12 months to August 2022.

Much of the forecast turned out to be wrong. By April this year, the consumer prices index measure of inflation was roaring ahead to 7.8% and the momentum was for it to go higher. And it did go higher, reaching 10.7% in November.

The pay review board took higher inflation into account, which is why low earners are in line for a near 10% rise. Nevertheless, with a 4% average recommended rise, there have been calls from many quarters for ministers to revisit the pay review body’s recommendation.

Yet the health minister, Steve Barclay, has taken an even tougher stance. In his letter to Hird setting out the context for next year’s pay review, he has urged continued restraint.

A 7.8% rise in the cost of living in the year to April 2022 and 10% rise to April 2023 would mean that a pay body offer averaging 4% this year and a similar award next year would lead to a near 10% inflation-adjusted pay cut over two years.

It is a pay gap nurses will want to close.

• This article was amended on 31 January 2023. An earlier version said Karen Mumford counted Adam Smith “as her principal hero”. In an interview to which the article links, she named Smith first among her “greatest influences” but he was not in the list of economists she cited as her “heroes”. The reference has been revised accordingly.