IF IT materialises, it promises to be the most bitter battle for control of a major Scottish company in a very long time. After many months of speculation, Danish and Dutch brewing groups Carlsberg and Heineken have signalled they intend to mount a consortium bid to break up the Edinburgh-headquartered Scottish & Newcastle, the UK's largest beer producer. Price tags as high as £10bn are already being touted round a drooling City.

The mood music from Copenhagen is all sweetness and light. Carlsberg, already a 50:50 partner in S&N's fast-growing Russian subsidiary BBH, would dearly love to reach agreement with S&N's board on a take-out price for the whole group. The Lex column in yesterday's Financial Times trotted out its own cliched encouragement for the continental raiders. "It looks like last orders at Scottish & Newcastle," it opened. "Hurry up, please, it's time," came the equally predictable concluding punchline.

In between, Lex warned anyone expecting "a Braveheart-style propensity towards independence" to look no further than the composition of that S&N board for reasons to expect early capitulation. Yet the previous day that same board, in a Stock Exchange announcement, had described the proposed bid as "unsolicited and unwelcome", and reaffirmed its confidence in its own future as an "independent group".

Boards do that, of course, even if only to squeeze the last penny out of any predator. But apart from the presence of non-executive director, Philip Bowman, who sold Allied Domecq to the French and ScottishPower to the Spanish, and ex-Hilton Group deputy CEO Brian Wallace, it's difficult to sustain the Lex allegation that S&N's current board is "a veritable who's who of recently-sold mid-size UK companies". I can point to at least five others who have, in the past, expressed strong views about maintaining a good stock of big independent Scottish-based businesses.

And let's not forget that S&N has been here before. In 1988, when the brewer was still headquartered on the site that now houses the Holyrood parliament, it was on the receiving end of a hostile bid from a buccaneering Australian called John Elliott. He had turned an obscure jam company down under into Elders IXL, already owners of Courage in the UK and brewer of Fosters, the now-ubiquitous Oz lager.

Twenty years ago S&N was run by a pillar of the Scottish Unionist establishment, Alick Rankin. He was Eton and the Guards. His wife a lady of the bedchamber in the royal household. In constructing a defence of his company, Rankin played a political blinder. First, despite some rather flimsy evidence on market overlap between S&N and Courage brands in a few stretches of middle England, he succeeded in getting the Elders bid referred to the Monopolies and Mergers Commission. There were suggestions at the time that Buck House had dropped a few supportive hints in appropriate ears.

Then Rankin summoned up heavier Caledonian artillery, ranging from a Malcolm Rifkind-led Scottish Office to a Campbell Christie-led STUC, to try to shoot Elliott down. It was the last hurrah for national resistance to external predation on Scotland's shrinking quoted-company base. But a decade that had seen the Royal Bank plucked from the jaws of HSBC and then, first, Arthur Bell then the Distillers whisky empire fall to Guinness, ended, in March 1989, with S&N escaping the clutches of Elders IXL.

Rankin claimed Rifkind had "laid his head on the line" to save what was, at the time, Scotland's largest manufacturing company. The competition authorities insisted their decision was all about preserving choice for beer-drinkers. But few believed them. In due course, S&N acquired Courage and control of the Fosters brand. John Elliott faced criminal charges back home and, a couple of years ago, declared himself bankrupt.

If Carlsberg and Heineken are rebuffed this time around, but then choose to launch a hostile bid, is there any chance that history might repeat itself? The first big question is, as we've already noted, how resolved the S&N board really is to fight for independence. One important straw in the wind is the announcement, late last month, that S&N chief executive Tony Froggatt (coincidentally another Australian) had decided to leave the group he joined in May 2003 and his rapid replacement by John Dunsmore, a one-time City drinks analyst turned brewing executive who has lived in Edinburgh for most of his career.

Might Froggatt have been more inclined to do a deal with the long-anticipated consortium? Was his sudden departure, despite claims that he only ever wanted to stay at S&N for five years, a sign he was losing the strategic argument over S&N's future with most of his board? Dunsmore's arrival in the top job certainly looks like S&N is already deploying its main lines of the defence to come.

However, this isn't a simple rerun of 1988/89. Globally, brewing is consolidating fast. Under Froggatt, S&N has played its own part in that process, responding to a flat market for beer in the UK by selling off its pub estate and then deciding, in 2004, to close its landmark Fountain Brewery in Edinburgh and an equally iconic plant in Newcastle.

And a near Edinburgh neighbour of S&N, the Royal Bank of Scotland, has just demonstrated how to construct a successful consortium bid to break up a rival, painstakingly negotiating all the regulatory hurdles to see off an agreed merger with Barclays and win control of Dutch banking group, ABN Amro.

Now that money talks as never before, governments don't put their necks on the line any more to ensure the continued independence of this business or that. But the government that answers for its actions where Alick Rankin's office once stood might just take a more uncompromising line. The SNP minority administration at Holyrood talked, before it gained power, of the need to stop Spanish predator, Iberdrola, buying control of ScottishPower.

It wanted to support national industrial champions, it said, because of their significance to preserving the vitality of any economy. And growing the Scottish economy is still this government's number one priority. So it would be surprising if Alex Salmond and his team simply stand back and let Carlsberg and Heineken break up Scottish & Newcastle. Heineken, which has its eyes on S&N's UK operations, might try to sweeten the pill by promising to move its own UK headquarters from Wimbledon to Edinburgh. Shades of Ernest Saunders house-hunting in the New Town all those years ago. But if beer wars do break out in Scotland, expect a serious political backlash before such horse-trading gets a look-in.