MINISTERS have been warned they must obtain firmer assurances from US drugs firm Pfizer over its long-term commitment to the UK if its proposed takeover of AstraZeneca is approved.

The Commons Science and Technology Committee says the promises made so far by Pfizer, which are limited to just five years, were of little value in an industry measuring progress in decades rather than years.

The committee is one of two cross-party House of Commons select committees to have taken evidence this week from the bosses of the two firms regarding the takeover, which is being strongly resisted by AstraZeneca.

In a letter to Science Minister David Willetts, who also appeared before the committee, the MPs said: "Science is a long-term enterprise and it requires a genuinely long-term commitment.

"We are not yet convinced this is what Pfizer is offering.

"If Pfizer is as committed to the UK as it claims, we hope it will voluntarily strengthen and lengthen the promises it has made.

"But the Government must be willing and able to hold Pfizer to account if necessary.

"We support the Government's efforts to attract foreign investment, but this must not be at the expense of UK science."