The scheme, run as a not-for-profit Community Benefit Society, ensures businesses and other organisations are transparent and honest in their tax affairs.

Frances O’Grady, TUC General Secretary, said the accreditation was an important part of corporate responsibility. ‘We are proud to support the Fair Tax campaign. Our taxes fund schools, hospitals and so many other important services that we all rely on.

‘Businesses depend on tax-funded services too. They get healthy and educated workers, roads to get goods to market, and law and order to protect them from rogue traders and crime. Firms that dodge their taxes are freeloading off the rest of us.

‘The Fair Tax Mark can help people decide if a company deserves their business. We hope it will reward those doing the right thing and make the tax dodgers think twice about avoiding what they owe.’

The accreditation comes at the end UK’s first ever Fair Tax Fortnight, which has also seen high street favourites, Timpson Group, announce their Fair Tax Mark accreditation and the release of new research about the public’s attitude to tax and good corporate conduct.

Paul Monaghan, chief executive at Fair Tax Mark said: ‘We are delighted that the TUC is now an accredited Fair Tax Mark organisation, taking the lead in demonstrating the importance of transparent tax practices.

‘It is estimated that €600bn of corporate profits are annually shifted to tax havens, with corporate tax revenue losses globally of €200bn per year - which equates to approximately £7bn of missing revenues in the UK. Fair Tax Fortnight celebrates organisations like the TUC that are seeking to do the right thing and are proud to pay their fair share of corporation tax. The recent polling released shows that this resonates strongly with the UK public - who want to shop with, work in and celebrate fair tax enterprises.’

Research commissioned by the Fair Tax Mark found that 70% of the public would rather shop with a business or work for a business which can prove it's paying its fair share of tax; and 61% would trust a business with the Fair Tax Mark more than one without it. A majority of the public say that they would switch the businesses they use in favour of one that has the Fair Tax Mark (51%) – with just 7% disagreeing.

Three quarters (74%) of those questioned support a call for all companies, whatever their size, to publicly disclose the taxes that they do or don’t pay in the UK - with just 4% of the public disagreeing.

And 59% say that the government and local councils should consider a company's ethics and how they pay their tax as well as value for money and quality of service provided – with just 15% agreeing that contracts should be awarded regardless of ethics and tax conduct.

Report by Rob Munro