GlaxoSmithKline has brushed aside Brexit jitters and announced that it is pumping £275m into its three UK manufacturing sites, dubbing the UK an "attractive location".
The investment will go to sites at Barnard Castle, Durham, Montrose, Scotland, and Ware in Hertfordshire, and GSK said "new employment opportunities" are expected to be created as a result.
Chief executive Andrew Witty said that the UK's "competitive corporate tax system" and skilled workforce helped the pharmaceutical giant come to its decision.
Mr Witty, who backed the Remain campaign during the referendum, said: "Today's announcement reflects further investment to support our pharmaceutical pipeline and meet growing demand for our innovative portfolio of newly launched products.
"It is testament to our skilled UK workforce and the country's leading position in life sciences that we are making these investments in advanced manufacturing here. From their manufacture in the UK, many of these medicines will be sent to patients around the world."
The UK's Business and Energy Secretary Greg Clark said: "An investment of this scale is a clear vote of confidence in Britain and underlines our position as a global business leader.
"GSK's recognition of our skilled workforce, world leading scientific capabilities and competitive tax environment is further proof that there really is no place better in Europe to grow a business."