Shire, the pharmaceuticals company that shifted its domicile to Ireland this spring, has made significant tax savings by moving its headquarters away from the UK ahead of controversial new tax legislation introduced earlier this year.

Angus Russell, the chief executive and former finance director who masterminded the company’s move to Dublin, described as “misleading” any suggestion that the British government had deferred plans to tax companies on profits earned abroad. His comments highlight that while the Treasury plans wide-ranging reforms to clamp down on UK companies avoiding profit tax by using lower-tax foreign subsidiaries, some have become law and are already having an impact.