Jars of Marmite, which is owned by Unilever, on sale in a branch of Tesco in central London, Oct. 13,2016. (Alastair Grant/AP)

LONDON — Since Britain voted to leave the European Union in a June referendum that rattled the world, the country’s prime minister has resigned, markets have tanked then recovered and the pound has plummeted, by one measure, to a 168-year-low.

Yet it wasn’t until Thursday that Brits perhaps first grasped the full gravity of what they had done.

The belated wake-up call came, as most paradigm-shifting realizations do, in the form of a breakfast spread. But not just any breakfast spread: Marmite, the sticky and impossibly salty yeast extract that only a Brit – in citizenship or in spirit – could love.

Because of Brexit, and particularly because of the fast-falling value of the pound, British supermarkets on Thursday morning were running out of Marmite. The development prompted mild states of panic from devotees, along with a reconsideration of whether leaving the E.U. is such a good idea after all.

"Nooooo. You are kidding me?!" said Johnny Birch, a 47-year-old decorator, when informed of the shortage.

Birch, who voted for Brexit, said he likes Marmite in the morning spread on toast and dipped into a boiled egg — a peculiarly British delicacy known as "soldiers."

"It gets you up and gets you energy," he said as he stood outside a Tesco supermarket in southwest London. "Our mornings won't be the same again. I want to stock up. It's a disgrace."

On Thursday evening, Birch got a reprieve from the need to hoard after the pricing dispute that had led to the temporary shortage was resolved. That will no doubt dishearten pro-European Marmite haters, who had finally found something about Brexit they can support.

“I've always loathed Marmite,” the author S.J. Watson wrote on Twitter. “Finally I see the point of Brexit.”

Surveys have shown that Brits are almost exactly split over whether they love or hate Marmite, much as they are over Brexit. (Hummus is the only food in Britain that’s more divisive.)

Thursday's short-lived shortage — future historians will undoubtedly dub it the Great British Marmite Crisis of 2016 — kicked off due to a price dispute between Tesco, the ubiquitous mid-market British supermarket chain, and Unilever, the supplier of Marmite as well as a long line of less controversial grocery store items, including Ben & Jerry's ice cream and PG Tips tea.

Although the shortage yielded much mirth on social media and in the supermarket aisles, it pointed to a possible disaster for the British economy as the pound continues to weaken.

“It’s a very visible sign of what’s happening. Currency markets are taking the view that trade will become more expensive post-Brexit,” said Paul Johnson, director of the London-based Institute for Fiscal Studies. “The markets are making a statement of concern about the future strength of the U.K. economy.”

That, Johnson said, will likely mean broad-based price increases. The Marmite flare-up on Thursday was only the start.

Britain’s normally rock-solid currency has taken a nasty fall since the country opted in a 52-to-48 percent June vote to leave the E.U. The pound has been particularly battered in recent days amid concern among traders that Britain is careening toward a "hard Brexit," one that will take it out of Europe's single market and end in high tariffs between the Britain and the continent.

Before the Brexit vote, the pound was worth nearly $1.49. As of Thursday, it was down to less than $1.22 — the sort of precipitous fall that is usually reserved for emerging market currencies. The decline has made the pound the world's worst performing major currency this year.

That has been a boon to British manufacturers, and has attracted bargain-hunting tourists to British shores. But it has also made foreign travel significantly more expensive for Brits, and is expected to yield sharply higher prices on imported consumer goods.

Tesco apparently balked at Unilever's attempt to raise its prices even on goods, like Marmite, that are made in Britain. The impasse, according to a statement from the supermarket chain, had caused "availability issues on a number of Unilever products."

At stores, supplies of Unilever products — Marmite included — were reportedly running low on Thursday. On Tesco's web site, a number of goods were completely out of stock.

But by Thursday evening, both companies reported that the matter had been resolved and that supplies of Marmite, as well as Unilever’s other products, would be back to normal in stores and online.

“We always put our customers first and we’re pleased it’s been resolved to our satisfaction,” the supermarket said in a statement.

Tesco said the price of Marmite for consumers would remain unchanged. It was unclear whether the company had persuaded Unilever to drop its demand of a reported 10 percent increase on the wholesale price. Unilever executives defended the proposed increase, noting the higher cost of supplies sourced in Europe and the lower value of pounds paid when corporate profits are counted in euros.

But Johnson said that inflation for consumers is unavoidable if the pound stays weak. And that, he noted, could do serious damage to British living standards, which have only recently begun to rise following the damage done by the Great Recession.

If wages don’t increase with prices, he said, “living standards stagnate or possibly fall.” The working poor could be hit hardest, given government plans to freeze benefits for the next three years.

“In a world where the price level is rising, it’s poor, working-age people who will be hit hardest,” he said.

But for now, at least, the threat of a Marmite-deprived Britain appears to have passed – for good or for ill.