'It's hard to keep up with lefties," the right-wing Tory MEP Daniel Hannan tweeted last week.

"AstraZeneca has gone from Evil Big Pharma to National Treasure simply because Americans want to buy it."

His sneer contained an element of truth, partly because of the £63 billion price tag put on the firm by Pfizer in its bid to buy it and partly because of its usefulness to a wider argument about "industrial strategy". But it is mostly because of the jobs and opportunities involved that a company few who don't read the financial pages had heard of became everyone's business last week.

And so it should be. If the deal went ahead and AstraZeneca swallowed it, it would be the biggest takeover in UK corporate history.

The deal was immediately rejected by the UK pharmaceutical firm's board on the grounds that Pfizer had "significantly undervalued" the company.

A series of mega-takeovers in the pharmaceutical sector has been rolling on for years, but this one is different, and not just because of its size. Now the need for Britain to build thriving industries over and above financial services is universally acknowledged, there is far less tolerance of national industrial champions being sacrificed to the principle of an open economy.

As a parade of business and science luminaries queued up to decry a potential deal, Business Secretary Vince Cable hinted the government would expand its definition of the national interest when deciding whether to intervene in takeover deals and mergers. Then Prime Minister David Cameron, accused of cheerleading for the deal by Ed Miliband, declared himself "not satisfied" with Pfizer's assurances, and determined to press them further. The business and political entanglement is made even worse because two of Cameron's key aides are closely connected to the drug giant.

Even without that extra political spice, the rights and wrongs of the proposed mega-merger have wider resonance. For a start, it is tailor-made for the neo-interventionist stance - essentially handing out good and bad marks for corporate behaviour - that Miliband and his advisers are hoping will propel him into Downing Street in a year's time. For Dr Jimmy Cooke of Edinburgh-based SVM asset managers, the bid is far less surprising than the political drama has made it appear. For investment professionals such as Cooke with shares in both firms, it is probably more good news than bad, though he concedes mergers lead to cost-cutting and job losses.

Cooke knows the pharmaceutical business: in a former life he worked for Glaxo Wellcome, spending three years at its site in Beckenham developing the anti-coldsore treatment, Zovirax.

Glaxo Wellcome, Britain's first multinational pharmaceutical, was then the third largest in the world. It merged with SmithKline Beecham in 2000 to form GlaxoSmithKline, a deal that put it one down from Pfizer in the global size-ranking and was a milestone in the sector's history of mega-mergers.

Cooke left the pharma industry and now helps manage SVM's Equity World Fund, which holds stakes in Pfizer and AstraZeneca, precisely because of the instability of an industry where one expensive clinical flop can be the difference between being predator and prey.

The turning point for him was a speech by the Japanese-American pharma entrepreneur Tachi Yamada, then head of Glaxo Wellcome's R&D.

Cooke said: "He expressed a view that research and development staff could be hired or fired as dictated by the needs of projects. Given the number of site closures that had been going on it was fairly clear to me that he considered most scientists as a commodity to be hired and fired at will, which made me think again about my career.

"One of the reasons that I didn't want to stay in the industry - along with being interested in investment - is that I knew these kinds of mergers were going to happen more and more.

"They have been going on a long time. It's difficult for UK authorities, who have to balance between protecting the open business environment that draws investors to the UK, and protecting the strategic interests of our industries.

"The alternative is to be protectionist like France, but that makes us uncompetitive on a global scale and it can lead to a very stifling environment."

Cooke cites the example of the UK car industry, currently said to be producing more vehicles than ever, but with not one of its iconic and venerable brand names British-owned.

He says he does not envy politicians required to pronounce on the proposed deal, buffeted as they are on all sides by conflicting advice: "All governments want to be popular, and need to satisfy different interest groups. At least they are in the position where they make demands of Pfizer."

But would Pfizer be held to those demands? There is plenty of reason to doubt it. Often cited here is the the Kraft-Cadbury deal, in which the American giant's solemn-faced promise to maintain Cadbury's Bristol factory melted like a bar of Dairy Milk left in the sun soon after the deal was done.

That fiasco, possibly the most notorious feat of corporate hypocrisy since Guinness reneged on its promise to keep its headquarters in Scotland after the hard-fought Distillers merger, prompted a revamp of the rules governing foreign firms buying UK ones.

The Panel on Takeovers and Mergers reviewed the laws and in September 2011 made changes to the Takeover Code, strengthening the hand of target firms, and demanded more information from bidders about their intentions after the deal, particularly on areas like job cuts.

These precedents enhance the sense of crossed fingers in some of the carefully worded assurances provided by Pfizer, which allow wriggle room if circumstances can be portrayed as having changed.

NOW the politicians' blood is up and they have the nation's attention, Pfizer executives are likely to get a hostile hearing when two parliamentary select committees - the Business Select Committee and the Science and Technology Committee - summon them to say if their intentions are honourable.

Meanwhile, Scotland's pharmaceutical research community will watch developments closely, though as many of our life-sciences academics receive research support from both Pfizer and AstraZeneca, they will not pronounce publicly on a preferred outcome.

Scotland has been successfully selling itself, Scottish Development International says, as "the ideal location for clinical and pre-clinical research and drug manufacture". It has a history of drug-discovery excellence and is home to nearly 150 pharmaceutical services and supply firms.

The head of department at one of Scotland's leading academic research laboratories, who asked not to be named, explained why he deplored the inexorable movement towards "one big pharmaceutical megacorp".

"I know other industries where that kind of dynamic has had a negative effect and there is a strong sense among us that retaining a strong research base in Britain is important for the UK," he said. "It might or might not be disastrous for jobs if this merger went ahead but it does seem unfortunate if the element of control was lost to the UK, as location is important.

"We do a lot of collaboration with the industry, and to take out a major player would be unfortunate, partly I admit because it's helpful for us to play one funder off against the other. But it is the creation of uncertainty that's damaging." His is another voice to add to the chorus of disapproval of the planned merger.

It has come from Michael Heseltine, Lord Myners, Lord Sainsbury, and former AstraZeneca chief executive Sir David Barnes, who fears Pfizer will act like a "praying mantis … sucking the lifeblood out of AstraZeneca."

Barnes's fear - echoed by Cable - is that it is not Britain's superlative science base that appealed to the New York-based Pfizer, but its low levels of corporation tax.

Stephen Boyd, assistant secretary of the STUC said: "You don't have to be a rabid protectionist to hold grave reservations about Pfizer's offer which would do nothing to boost jobs, competition or investment in R&D. Indeed, it's inevitable that further consolidation in the pharmaceuticals sector will lead to job cuts, higher prices and less quality UK-based research.''

Boyd added: "The UK government's relaxed attitude to the deal exposes the weakness of the commitment to its own much-vaunted industrial policy.

"AstraZeneca is a genuinely world-class company operating in one of the very few sectors where the UK remains a major global player. It's a strange industrial strategy that supports a deal that at a stroke will seriously undermine capacity in the science, research, manufacturing and export bases.

"It's worth noting in passing that the key issues of ownership and control are conspicuous by their absence from the debate over Scotland's economic future. The White Paper contains precisely zero references to ownership."

Now the pendulum has swung back towards industries rich in intellectual property, manufacturing and value-creation rather than financial smoke and mirrors, the questions of how to nail down Britain's long tradition of excellence in pharma sciences has taken on a new urgency.

Imagining the UK economy of the future, we have learned the hard way that the literal laboratory of pills and potions beats the figurative laboratory of uber-free-market corporate slicing and dicing.

Britain and the international pharmaceutical world

After the United States and Japan, the UK is the world's biggest spender on pharmaceutical research and development, with around 10% of the total, despite only representing about 2%-3% of the world market for drugs.

In European terms, Britain - possibly because of the presence of a client on the scale of the NHS, and a strong academic heritage in chemical sciences - has 23% of the total. This is followed by France (20%), Germany (19%) and Switzerland (11%). The research strength in the UK also reflects the wave of global mergers that have given British boffins access to important international collaborations.

The roots of the industry go back to the 19th century, when Thomas Beecham established the Beecham's Pills laxatives business in the 1840s. This later became the Beecham Group, with the first modern drugs factory opening in St Helens, Lancashire, in the 1850s. Many decades and many mergers later, the firm became part of GlaxoSmithKline.

Giants that helped build up the UK's global reputation include Ayrshire-born Sir Alexander Fleming (1881-1955), inventor of penicillin.

The sector expanded hugely in the 20th century, with the formation of Glaxo Laboratories, and the arrival of Pfizer, which operated in Kent from the 1950s.

But Pfizer's decision in 2011 to close its factory in Sandwich, with the loss of hundreds of jobs, prompted the Westminster government to introduce a life-sciences strategy, increasing research and development tax credits and creating a "patent box" that lowers the tax rate to 10% on profits earned from inventions patented in the UK.

The NHS is not always an asset, as it is also blamed for making clinical drug trials difficult, and in the past decade Britain has seen its share of these tests shrink, despite government efforts to streamline a complicated approvals process. Much of the testing has moved into Europe, where processes are quicker.