Following a brief 30 minute with Pfizer chief executive Ian Read after today's hearing Mr Miliband said: "There are serious concerns about this proposed takeover. There are too many unanswered questions about British science and British industry.
"This takeover will affect our country for decades to come. That is why David Cameron should act now and have a proper test about whether it is in our nation's interests. If it is not, he should block the deal."
This morning Pfizer has "gone hostile", not with a renewed bid but with an appeal made directly to the shareholders of AstraZeneca.
MPs on the business committee are sceptical that AstraZeneca would remain committed to Britain if taken over by US giant Pfizer.