The takeover drama of Britain's AstraZeneca by US drugs giant Pfizer has now reached British prime minister David Cameron's doorstep.
In a letter to Cameron, Pfizer chief Ian C. Read tried to address concerns over the bid and said it had no plans to cut jobs or close labs in UK.
There have been worries that a takeover of AstraZeneca which employs 6700 people in UK could lead to a cut down of staff.
On Wednesday, scientific bodies raised concerns about possible UK lab closures following a Pfizer deal.
Pfizer however told Cameron that it would go ahead with Astra's planned research and development base in Cambridge and retain its Macclesfield manufacturing facilities.
Meanwhile Pfizer made a fresh offer and raised the price it is offering for Astra to £50 a share, valuing the firm at £63 billion.
Pfizer's initial offer in January was worth £46.61 per AstraZeneca share valued at £58.8 billion.
Astra said the new terms offered were "inadequate, substantially undervalue AstraZeneca and are not a basis on which to engage with Pfizer".
Cameron's spokesperson said the UK government regards the potential takeover bid as a matter for the respective boards and shareholders of the two companies.
"The PM has received a letter from the Chief Executive of Pfizer and today spoke to the Chairman of AstraZeneca who set out the Board's confidence in AstraZeneca's strategy as an independent company. The government is determined to secure great British science, research and manufacturing jobs in the life sciences sector. We want to see the sector continue to flourish and grow, with Britain retaining its scientific leadership and key R&D operations for the long-term, as well as its role as a leading manufacturing base. That is also the clear and consistent message we have given to Pfizer".
"The letter from the chief executive of Pfizer is a positive sign with significant undertakings on research, jobs and investment. The government will consider these proposals carefully as to whether they offer sufficient protection of our priorities. Obviously it remains unclear whether Pfizer's takeover will actually proceed," the spokesperson said.
On the letter to Cameron, Read says "I am writing to you to address the concerns of the UK government and science community and your desire to have firm and enduring assurances from us about our commitment to the UK and its life sciences agenda. We believe the industrial logic for a combination between Pfizer and AstraZeneca is compelling. A combined company would bring together powerful and world leading research expertise in key therapeutic areas such as oncology, inflammation and cardiovascular and metabolic disorders, in which the world class academic research resources in the "golden triangle" of Oxford, Cambridge and London would represent a vital component".
He added "Pfizer commits to establishing the combined company's corporate and tax residence in England. Pfizer commits to complete the construction of the currently planned AstraZeneca Cambridge campus, creating a substantial R&D innovation hub in Cambridge. Pfizer will base key scientific leadership in the UK who will lead all European and certain global R&D functions based in Cambridge. Pfizer commits to base the combined company's European business HQ in the UK and commits to invite at least two AstraZeneca Board Members to join the Board of the new company".