Pfizer’s talks to acquire botox-maker Allergan in a $150bn (€140.8bn) deal, the global drug industry’s largest ever, that would see the US drug giant re-domicile in Ireland accelerated yesterday, even as the US Treasury prepared to clamp down further on such tax inversions.

Ireland’s tax regime may again face the international spotlight, at an uncomfortable time for the country, after two of the world’s pharmaceutical giants yesterday confirmed they are in talks over a mega billion dollar merger that appears to be driven by Irish tax considerations.

The huge strengths of Ireland’s exporting base — which helped the country get through its worst ever economic crisis — were highlighted yesterday in the annual publication of the list of the top exporters on the island.