I eagerly anticipated my first trip to a London pub after the easing of November’s second national Covid-19 lockdown. But there was a snag.

Pubs in areas with tier 2 restrictions, like London, could only serve alcohol to customers if accompanied with a “substantial” table meal. It meant that I also had to come prepared to eat some quintessentially British pub food: bangers and mash, scampi with chips, or a Sunday roast maybe. But a scotch egg was not at the top of my imaginary list.

That this humble bar snack may not even be British is beside the point. Ever since cabinet minister Michael Gove confirmed that the scotch egg qualified as a substantial meal under the Covid-19 guidelines, this robust morsel has enjoyed a surge in demand. Last week, one wholesaler reported a ten-fold increase in demand for the soft-boiled egg, which comes wrapped in sausage meat that is then rolled in breadcrumbs and fried.

At the pub I went to, a Wetherspoons in south-west London, there was a palpable lack of festive spirit, with measly Christmas decorations to complement the absence of holiday cheer and no scotch egg on offer in the end. Even so, I was slightly baffled to find I would have to order three starters to satisfy the tier 2 requirements. Each seemed substantial enough to count as a meal by itself, but the waiter disagreed. It’s just another bewildering reality to add to this year’s long list: an eight-inch pizza is not substantial, but a scotch egg is.

To be fair, there has been some confusion on this point, even at the highest levels of government. The question has seemed to scramble the minds of senior politicians: just how many scotch eggs is substantial enough?

Maybe they should have turned to the grand dame of British cookery: Mrs Beeton. According to Rebecca Earle, historian of food at the University of Warwick, a grand total of six scotch eggs was regarded as enough to feed three to four people in her 1861 Book of Household Management.

The snack certainly divides opinion. A straw poll of my friends, who are in their twenties, produced mixed reviews. One called them a “British delicacy”, while another went for “underwhelming” and “a bit random”. A YouGov poll last year of British culinary classics found that only about half of respondents who had tried a scotch egg liked it — compared to the more than 80 per cent who tried and approved of a Sunday roast, fish and chips or a bacon butty.

Food writer and historian Seren Charrington-Hollins acknowledges that scotch eggs may not be the most refined of foods “and their pedigree is somewhat disputed, but nonetheless they are considered a British culinary treasure”. In fact, she points out that there are disputes as to whether the snack is as British as we think: “There are plenty of stories about the origin and those that wish to stake their claim as the inventor of the beloved egg, but none of them confirmed by hard evidence.”

One theory suggests that the scotch egg was an export from the British Raj. Ms Charrington-Hollins points out that the snack bears an “uncanny resemblance” to the Mughlai dish nargisi kofta, which consists of hard-boiled eggs coated with cooked, spiced mutton that is then fried.

Ms Earle adds that there are similar dishes from many parts of the world — emerging simultaneously in different areas. “People in different parts of the world can have the same general idea without there being a necessary connection,” she says.

Despite the controversy and regardless of whether you love, hate or are not particularly bothered by the popular picnic snack, the scotch egg has been having a moment. Yet it may be a short lived one. After London is lifted into the more stringent tier 3 category of restrictions from Wednesday, the government has signalled last orders on pub meals — substantial or otherwise.