LONDON — No need to panic. Or maybe there is — just a little.

Britain on Thursday offered a snapshot of a nation trying to come to grips with a possible “no-deal” exit from the European Union — meaning it would be cut loose without any prearranged pacts on trade, travel and security with its longtime partners.

British officials have long promised this was unlikely, because it would introduce a mountain of costly red tape, tariffs and friction at the borders.

But the government has now released its first “technical notices” on how British citizens and businesses might be wise to prepare for the country’s possible crash out of the E.U. next year without a divorce settlement in place.

For weeks, there has been a string of doomsday scenarios in the British news media about what could happen if Prime Minister Theresa May’s negotiators fail to strike an agreement with Brussels.

There has been speculation — floated by think tanks, business lobbies and hospital administrators — a “no-deal Brexit” could create total havoc.

Imagine, they say, days-long traffic jams at the ferry ports and Euro-tunnel; empty shelves at the grocery markets; shortages of fuel and medicines; chaos at the airport immigration booths; and police locked out of cross-border databases about terror suspects.

There have also been stories about a “sandwich famine” and the British Army — seriously — being deployed to suppress civil unrest.

Last month, the British Sandwich Association warned a no-deal Brexit could affect the range of luncheon items on offer if it became harder to import out-of-season ingredients with a short shelf-life, like lettuce and tomatoes.

It did not help matters that, on Thursday, the government itself also warned the 3,000 or so units of donor sperm from Denmark delivered to Britain each year might also be slowed down — as transports of human tissue and cells, in a no-deal scenario, would require new written agreements with the relevant E.U. licensed establishments.

“Let me assure you that, contrary to one of the wilder claims, you will still be able to enjoy a BLT after Brexit, and there are no plans to deploy the army to maintain food supplies,” said Brexit Secretary Dominic Raab after the release of 148 pages in 25 advisories, the first tranche of 80 documents on a possible no-deal world.

But Thursday’s advisories — even after being reportedly softened by the government — still conjure up a lot of hassle, added cost and dysfunction.

In the past, May and her pro-Brexit cabinet repeatedly assured Britain a sweet deal with Brussels was just around the corner.

Now government ministers say it is about 50-50 chance of a favorable Brexit deal.

The British public is even less optimistic, according to the most recent polling. 

In its first papers on a no-deal Brexit, May’s government warned the cost of credit card payments between the Britain and Europe will probably increase and so will the cost of Internet purchases — totaling in the billions — from Europe.

Brits working and living in Europe could also lose access to British banking — and pension services. Some 250,000 British retirees live in Europe.

There will likely be customs checks and delays for British companies exporting to Europe, the government advised, as “the free circulation of goods between the U.K. and E.U. would cease.”

British hospital officials have warned a no-deal Brexit could hurt patients. Raab said the pharmaceutical companies already warehouse 200 medicines in case of shortages — and more is on the way.

“We will be working with industry around stockpiling of medicines for a working assumption of six weeks,” Raab said.

Raab said the government was planning to hire 9,000 more civil servants to handle Brexit, in addition to 7,000 bureaucrats already tending to the divorce.

The Confederation of British Industry, the nation’s top business lobby, warned, “these papers show that those who claim crashing out of the E.U. on World Trade Organization rules is acceptable live in a world of fantasy, where facts are not allowed to challenge ideology.”

Currently, there is frictionless trade and zero tariffs for trade between Britain and its European Union partners.

Barely 200 days remain before Britain exits the E.U. in March 2019, and much about the future relationship with the continent remains unknown.

The opposition Labour Party’s Brexit spokesman, Keir Starmer, said May’s government was “now moving into panic mode.”

“If the publication of these documents is just a crude attempt by ministers to dress up the severe consequences of a no-deal Brexit as somehow acceptable, the whole exercise will be pointless,” Starmer told BBC Radio.