Criticism of Buckfast wine has little to do with its 15 percent alcohol content, which is only slightly stronger than some table wines. Instead, critics cite the combination of alcohol and caffeine, which the Food and Drug Administration has already addressed in the United States. In Scotland, there is heightened concern about the demand from younger drinkers, some of whom seem to use Buckfast as a convenient alternative to mixing alcohol with energy drinks and caffeinated soft drinks. “There is no doubt that caffeine-alcohol mixers make wide-awake drunks,” added Mr. Simpson, a medical doctor. “You are more likely to drive, and there is much more of a sexual risk. If you drink enough alcohol you eventually become comatose, but if you combine it with caffeine you can go through a fairly aggressive phase before you become comatose.”

His bill would limit the caffeine content of all alcoholic drinks. He has allies among other opposition parties, and the Scottish government says it is considering whether to give support.

Under the plan, caffeine would be capped at 150 milligrams per liter of alcoholic drinks, the limit in Denmark. Buckfast contains more than double that level, or the caffeine equivalent of about three cups of freshly brewed coffee. Critics like Mr. Simpson cite a 2009 report for the Scottish prison service, based on research at an institute for young offenders, which concluded that “the salience of one brand, Buckfast tonic wine, was noteworthy.”

The brand “dominated wine consumption,” ranked as the favorite drink of four in 10 respondents, and was consumed by 43.3 percent of the respondents before they committed a crime, the report said.

In 2010, the police in Strathclyde, Scotland, said Buckfast wine was mentioned in 5,638 crime reports from 2006 to 2009.

The leadership of Buckfast Abbey is famously publicity-shy and, its head, Abbot David Charlesworth, declined to speak to a reporter.