George Osborne has insisted securing British jobs is the Government's "sole interest" amid calls for ministers to intervene over US pharmaceutical giant Pfizer's takeover bid for AstraZeneca.
The Chancellor said he would back "any arrangement that delivers" for the UK, and accused Labour of hypocrisy in suggesting that politicians should block the move.
The comments came after it was announced that MPs are to question senior executives from Pfizer over its £63 billion offer for the UK-based firm.
The Business, Innovation and Skills Committee will also question officials from AstraZeneca, which has so far rejected the overtures.
The committee is likely to seek assurances from the US firm about job security if the takeover goes ahead.
Unions have called for an urgent meeting with Business Secretary Vince Cable to press the case for jobs, amid speculation that Pfizer could be planning to make a hostile bid.
Unite assistant general secretary Tony Burke said: "The workforce and the unions have acted in a responsible manner and shown remarkable patience, but that is now wearing thin. Ed Miliband's sensible intervention at the weekend for a national interest test should be acted on. Neither the German or the French governments would be simply waving through a takeover on this scale.
Mr Cable said the Government had been "looking at the options around the public interest test" after Labour leader Ed Miliband demanded a full assessment of the potential deal.
The Labour leader has written to David Cameron calling for the publication of any analysis the Government has made of the proposal and claimed the Prime Minister had been acting as a "cheerleader" for the proposed deal.
He proposed widening the scope of the public interest test to take in industries of strategic importance - such as the high-value scientific research carried out by AstraZeneca.
The Government can currently intervene on mergers or takeovers where there is a national security issue, an issue of media plurality, competition concerns or if it could affect financial stability.
Asked about reviewing the test, the Business Secretary said: "Obviously we are looking at this option amongst others, I'm sure you wouldn't expect me to go into all the detail and the discussions we are currently having between the two parties to the proposal.
"What we are endeavouring to ensure in the Government is to make absolutely sure Britain's excellent science base and pharmaceutical research is properly protected, manufacturing in the UK, decision-making, those are the issues we are talking to the companies about."
Mr Cable said he had spoken to the chief executives of both firms and stressed that the Government was "strictly neutral" between the two.
Mr Cameron has said the Government had received "robust" assurances from Pfizer about protection for British jobs and research under the proposed deal and stressed it was a decision for shareholders.
The Liberal Democrat Business Secretary said there was a "lot of small print to study" in the assurances given by Viagra manufacturer Pfizer.
"We publicly welcome the fact that a letter has been issued by the company which underlines the importance we attach in Government to protecting British science and jobs and investment and manufacturing and decision-making in the UK but obviously there is a lot of small print to study, the question about how these obligations are binding and, of course, we're talking about two companies here and we're strictly neutral as between the two."
He said that the British competition and merger regime was non-political in the way it applied "but there is an important national interest here".
London Mayor Boris Johnson said ministers needed to ensure that Pfizer was genuinely committed to continuing research and development in the UK.
"It is of great importance to Britain so I don't think politicians can be entirely aloof from this," he told LBC
"I am not taking a position against the deal necessarily but it would be very important to establish that Pfizer is genuinely committed to R&D in this country and that it won't in any way damage what is the incredible success - particularly of London and the South East - in dominating the European scene in life sciences."
Mr Osborne said: "Our sole interest here is in securing good jobs in Britain, good manufacturing jobs, good science jobs.
"That's what I'm interested in and we'll support any arrangement that delivers that for Britain.
"We make no apologies for fighting for Britain's national economic interest and we'll take no lectures from the last government that virtually destroyed the British economy, and time after again when there were takeovers did nothing to protect Britain's national economic interest."