Pfizer defies Obama with $150 billion mega-merger with Botox-maker Allergan

US drugs giant Pfizer has incurred the wrath of President Obama as the maker of Viagra was set to announce the $150 billion (£99 billion) takeover of Botox producer Allergan to create the world’s biggest drugs company based in low-tax Ireland.

The so-called tax inversion deal comes more than year after Pfizer failed in a similar style, tax-driven £69 billion bid for AstraZeneca which would have seen it relocate to the UK.

This all-share deal will see Pfizer redomicile itself to Ireland, where Allergan is already based, although both companies’ shares are listed on the New York Stock Exchange.

Such a move would see Pfizer escape the US’s 35% corporation tax in favour of Ireland’s ultra-low rate of 12.5%.

Last year and again last week the US Treasury, under orders from Obama, tried to tighten rules against such inversion deals.