The ongoing row over corporation tax and 'morality' has led Ernst & Young's managing partner for Europe, Middle East and Africa to call on politicians to turn their words into action and change the law.

Mark Otty said trying to impose a moral tax code was destined to fail as businesses had a duty to pay the lowest rates legally possible.

Speaking at the World Economic Forum in Davos, Otty told The Telegraph: 'The only way you can resolve this issue is through a legal code. I don't see how you can have any assessment on payments of tax other than what is in the statute. The simplest solution is to stop banging on about morality and change the law.'

The comments were made in the wake of Prime Minister David Cameron's vow to clamp down on tax avoidance.

Cameron's phrase that businesses needed to "wake up and smell the coffee", provoked a backlash from US coffee chain Starbucks, who threatened to withdraw a planned £100m UK investment programme if the sniping did not stop.

Kris Engskov the managing director of Starbucks UK slammed Cameron for "singling the business out for cheap shots", demanding to meet the PM on Friday to thrash out their differences.

Conservative party chairman Grant Shapps denied that Starbucks was being singled out.

Starbucks later refuted the claim that the meeting had been urgently arranged, stating that it was "long-scheduled."

For fresh analysis into the Starbucks saga, read Coffee bean accounting, Alex Hawkes' article on how the coffee chain compares to that of its rival, Costa.