Investors are demanding that funds stop supporting companies that use tax-dodging schemes. By doing so, campaigners claim, firms take cash away from hospitals, schools and other public services, particularly in poor countries.

But the issue is not just about the moral imperative, warned Mark Robertson of the responsible investment research service Eiris.

“Tax avoidance also creates real financial risks for investors,” he said. “There’s compliance risk, which can stem from complicated and costly disputes. But there’s also the significant reputational damage in the form of negative publicity arising from aggressive tax evasion or avoidance.

“As a consequence investors should look at tax avoidance from a risk management perspective, irrespective of their own opinions or ethical stance on the issue.”

For example, Vodafone has come under heavy criticism in the UK about its tax payments. Meanwhile the commodities giant Glencore, which is holding its first AGM in May, has also been accused of tax-dodging in Zambia, one of the world’s poorest countries, although the firm denies the accusations.

In the last few days there has been widespread criticism of the online retailer Amazon after it was revealed that UK tax authorities were investigating the firm. Questions have been raised about why it paid no corporation tax on sales of more than £3bn and whether it avoided tax by allocating sales to a Luxembourg firm.

“When companies dodge their taxes, it hits hospitals, schools and other public services – and the millions of people who need them,” pointed out Joe Stead, senior economic justice adviser at the charity Christian Aid.

“In poor countries especially, tax-dodging costs lives – and for some ethical investors, that matters. They want the companies they invest in to thrive, but they want the same thing for the societies where they operate.”

While the charity is keen to publicise the negative effects of a major company attempting to avoid tax, the charity also pointed to the financial grounds for avoiding the firms.

“Becoming known as a tax dodger can damage a company’s reputation and lead to costly penalties being imposed by governments,” said Mr Stead, pointing to Barclays’ recent run-in with the UK government.

To date, there are few ethical funds that have taken on board investors’ concerns about tax-dodging companies. But that is likely to change, according to Mark Robertson.

“The issue of corporate tax avoidance is of increasing concern to consumers, and this will likely lead more investors to look at it alongside all the other sustainability issues they consider when investing.

“Few UK ethical funds have specific investment policies to address tax avoidance, but this will change as governments and the public step- up their pressure on companies to tackle the issue.”