The Government's flagship business policy to put workers on company boards has been left in tatters after big firms made a mockery of the idea.

A Mail on Sunday survey of the 100 biggest listed companies found none had appointed a worker to its board of directors since the reforms came into force on January 1.

Instead, more than a third of companies have taken advantage of watered-down rules to appoint existing directors as 'representatives' of their firm's workers.

Existing board members at Royal Bank of Scotland, easyJet, WPP, Morrisons, Legal & General, Diageo and Just Eat have all accepted the newly-created roles, which in some cases come with thousands of pounds of extra pay.

Many of the directors who now supposedly represent the interests of ordinary workers are extremely wealthy – and highly-paid – business titans who hold a string of powerful roles in the City.

The list includes Javier Ferran, chairman of FTSE 100 drinks giant Diageo, former Royal Mail boss Dame Moya Greene and City financier Edward Bonham Carter, the brother of Bafta-winning actress and Harry Potter star Helena Bonham Carter.

Some 'worker representatives' will receive up to £600,000 a year while carrying out their new duties, The Mail on Sunday probe found. The revelations will be seen as an embarrassment for the Prime Minister as she fights to stay in No 10.

Theresa May's promise to put the Conservative Party 'at the service of working people' was part of her pitch to counteract the rising popularity of Jeremy Corbyn when she became Prime Minister in 2016. She pledged to put workers on boards and blasted the 'narrow social and political circles' that controlled the FTSE 100.

'We're going to have not just consumers represented on company boards, but workers as well,' she said. 'We're the Conservative Party, and yes, we're the part of enterprise – but that does not mean we should be prepared to accept that 'anything goes'.'

However, the Government's updated UK Corporate Governance code, which took effect from January 1, allowed listed companies to invent their own system for 'engaging' with employees. They can even ignore the directive entirely if they explain their decision to investors.

In The Mail on Sunday's probe, 34 companies said they had given existing non-executives responsibility for representing workers.

That made it the most favoured option among big firms. A further 35 have not declared their response to the new rules. Eleven have formed a workers' advisory panel and nine have adopted alternative arrangements. Ten declined to comment.The final company, Scottish Mortgage, is an investment trust.

Luke Hildyard, of campaign group the High Pay Centre, said: 'The failure of companies to appoint workers on boards is a major embarrassment to the Prime Minister and reflects badly on the companies themselves.'

One of the most controversial appointments is likely to be Javier Ferran at Diageo. A respected Spanish businessman, he earns £600,000 a year as chairman of the firm. His City portfolio comprises a boardroom role at Coca-Cola European Partners and he was a senior adviser at private equity firm Lion Capital.

Ferran was previously chief executive and president of drinks company Bacardi, and has served on the boards of Primark owner Associated British Foods and SAB Miller, the brewing giant behind Peroni and Grolsch.

EasyJet has appointed former Royal Mail boss Moya Greene to protect workers' rights

Moya Greene outraged workers and unions in 2017 when she sought to close Royal Mail's defined benefit pension scheme while guarding her own generous pension payout of £200,000 a year as chief executive.

But now she will collect £60,000 in fees as the non-executive director at easyJet who has been tasked with protecting workers' rights. She also sits on three board committees.

Edward Bonham Carter will be the workers' representative at media giant ITV while juggling a number of high-profile City roles, including vice-chair of Jupiter Fund Management and non-executive director of property giant Land Securities.

RBS non-executive director Lena Wilson will receive an additional £15,000 in fees to attend meetings with employees and feed back their views to top brass. The Scottish business leader received a total £148,000 in fees in 2018 for her role at RBS, which included £20,000 in benefits.

Existing board member Tony van Kralingen will be taking up the baton for workers at Morrisons. He receives £102,000 – ten times the average salary of a supermarket cashier. He is also head of the Cabinet Office's procurement arm, the Crown Commercial Service.

Former HSBC banker Irene Dorner will receive an extra £15,000 in fees representing employees at Rolls-Royce, which has been slashing thousands of middle-management jobs and back office staff. As a non-executive, Dorner receives £76,000 in total for part-time work – almost twice the average full-time salary of Rolls-Royce's employees.

By contrast, some FTSE 250 firms have welcomed workers to their boards. Capita appointed Lyndsay Browne and Joseph Murphy to its board last week after a competitive process involving 400 employees. They will each earn £64,500 a year on top of their normal salary to carry out their duties.

A spokesman for the Department of Business, Energy and Industrial Strategy said: 'The UK Corporate Governance Code now requires companies to have at least one worker on their board or, if they decide otherwise, explain what alternative arrangements are in place and why it considers that they are effective.

'Any company not complying with this must report to shareholders annually on why they have not done so.'

A spokesman for Diageo said: ‘As Chairman, Javier Ferran, will provide effective leadership and engagement with our workforce and will not be paid extra for this work.’