Derek Brownlee, taxation executive at the IoD, made this comment in a letter to the FT in which he re-affirmed the institute's opposition to EU-wide tax harmonisation.

'The IoD has been urging such a course of action for a long time,' Brownlee said with reference to the amendment of treaties.

'Many long-standing aspects of the UK corporate tax system are being challenged in the courts on EU law grounds.'

He went on to say that amending the treaties would 'prevent a big burden in the form of additional regulation and leave UK policymakers free to concentrate on a subject of much more fundamental importance to UK business: is our tax system competitive, not merely within the EU, but internationally?'