LONDON — The British government is pulling out all the stops for Scotland with a referendum on independence two months away, going so far as to lobby the U.S. government to allow the importation of that famous Scottish delicacy made from sheep’s innards, haggis.

The problem, it seems, is sheep lungs, which the United States banned for consumption in 1971. But lungs are vital to traditional haggis, which usually also contains minced sheep heart and liver, mixed with onion, oatmeal, suet and spices. It’s all stuffed into a sheep’s stomach, which is then simmered for several hours. Delicious, no?

Well, it is rather nutty and flavorful — helped, of course, less by the common side dishes of mashed rutabaga and potato than by the other traditional accompaniment, Scotch whisky.

Needless to say, there is a lot of debate about the origin of this delicacy, which is particularly favored on Burns Night, Jan. 25 — a celebration of the birthday of Robert Burns, considered Scotland’s national poet — and often on New Year’s Eve, or Hogmanay, when its appearance is sometimes met with bagpipes.

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In 1786 or 1787, depending on the source, Burns wrote a poem, “Address to a Haggis,” in which he hailed it as the “great chieftain o’ the puddin-race!” Since then, he, haggis and Scotland have been linked in the popular consciousness.

But all those Scots in America have been deprived of proper haggis, which could also be an export market of several million dollars. Despite U.S. production of “lung-free” haggis, it’s not the real thing.

There remains, apparently, a shocking lack of knowledge about haggis. According to a not-very-scientific online survey in 2003, carried out by the haggis manufacturer Hall’s of Broxburn, one-third of U.S. visitors to Scotland believed haggis was an animal. Nearly one-quarter thought they could catch one.

The problem is bigger than haggis, however. British lamb has been banned from the United States since 1989 — amid the crisis over bovine spongiform encephalopathy, better known as mad-cow disease — and sheep lungs were banned because of the risk of contamination by scrapie, a variant of the same disease. Only last year, the United States agreed to allow the importation of British beef again, although British goats remain banned.

So the United Kingdom’s environment secretary, Owen Paterson, made a visit to Washington last week to lobby for haggis, which he made a centerpiece of his trip.

“I will continue to do everything I can to boost exports of everything from whisky to haggis to support Scotland’s farmers and rural economy,” he said.

Upon his return to Britain, a breathless kingdom was told “progress” had been made, but that the barriers still stood.

In a statement, Paterson spoke of a “specialist food sector” in the United States worth $85 billion a year; in Britain, the market for haggis alone is about $25 million. He said he had met with U.S. Agriculture Secretary Tom Vilsack, “and other members of President Barack Obama’s team,” as well as with various companies.

“We’ve made progress at opening up new markets for top-quality British produce, including cheese, confectionary, beef, lamb and haggis,” he said.

Paterson was clearly heeding the injunction with which Burns ended his ode, here in translation, to haggis:

“You powers, who make mankind your care,

And dish them out their bill of fare,

Old Scotland wants no watery stuff,

That splashes in small wooden dishes;

But if you wish her grateful prayer,

Give her a Haggis!”