Prime Minister says he needs 'more assurances' about Astra Zeneca take-over

David Cameron has insisted US pharmaceutical giant Pfizer must provide more assurances about its commitment to Britain amid concerns over its takeover bid for AstraZeneca, which employs more than 2,000 people in Macclesfield.

The Prime Minister said the UK "benefits massively" from foreign investment, and warned that the row must not trigger a retreat to protectionism.

But he indicated that the American firm had yet to convince him that the purchase would be in the national interest.

Answering questions from Macclesfield MP David Rutley in the Commons, Mr Cameron said the commitments made so far - including retaining at least 20% of the research and development workforce in the UK - were "encouraging".

"Let me be absolutely clear, I'm not satisfied, I want more. But the way to get more is to engage, not to stand up and play party politics," he said.

"The more we can do to strengthen the assurances the better."

AstraZeneca has so far resisted approaches from its rival, but executives have not given up hope of completing a £60 billion-plus deal - potentially the biggest ever foreign takeover of a British company.

Fears have been raised that resulting cost-cutting could cause the loss of thousands of highly-skilled jobs and undermine the UK's science base.

Mr Cameron dismissed suggestions from Labour leader Ed Miliband that he was "cheerleading" for the deal by tasking the Cabinet Secretary and ministers to discuss the situation with both companies.