A biopharmaceutical firm is to axe 700 UK jobs, transfer another 300 roles overseas and open a new UK research and development centre.
The £330m investment by AstraZeneca to set up a global HQ in Cambridge is expected to create 2,000 jobs.
Research work will stop at Alderley Park, Cheshire, where 2,900 people work. A majority will go to Cambridge, where London staff will also move.
Unions said moving the jobs would be a massive blow to north-west England.
'At a loss'
Unite national officer Linda McCulloch, said: "AstraZeneca's decision to relocate over a thousand jobs to Cambridge is... creating a skills crisis for the [north-west] economy.
"After 40 years of success and hundreds of millions of pounds of investment, we are at a loss as to why AstraZeneca is now pulling out of Alderley Park."
Pascal Soriot, the firm's chief executive officer, said Cambridge was picked because of its scientific workforce and institutions.
"This is a major investment in the future of this company that will enable us to accelerate innovation by improving collaboration, reducing complexity and speeding up decision-making," he said.
"The strategic centres will also allow us to tap into important bioscience hotspots, providing more of our people with easy access to leading-edge academic and industry networks, scientific talent and valuable partnering opportunities."
"Approximately 1,600 roles will relocate from Alderley Park over the next three years, with a significant majority going to the new centre in Cambridge and the remainder to the company's nearby Macclesfield facility or sites overseas."
At least 700 non-R&D roles are expected to remain at Alderley Park.
The firm said that Cambridge University, local hospitals and biotech companies offered a talent pool and opportunities for collaboration.
"Cambridge, which boasts strong links with London-based research institutions, is a world-renowned bioscience hotspot that rivals the likes of San Francisco and Boston," Mr Soriot said.
"I believe that the investment greatly increases the chances that the next generation of innovative medicines will be invented and manufactured in Britain."
AstraZeneca currently employs about 6,700 people in the UK.
"I recognise that our plans will have a significant impact on many of our people at our sites in Cheshire and London and the surrounding communities," Mr Soriot said.
"We are fully committed to treating all our employees with respect and fairness as we navigate this period of change."