Brexit negotiators 'very gloomy' over trade deal, with talks on 'knife's edge.' Again.

Sound familiar? It is. Even Brexit obsessives have lost track of how many "crunch times" have come and gone over these many months and years of negotiating Britain's exit from the European Union.

All that to say that Brexit talks have still not concluded. Negotiators met in the London over the weekend and worked until late at night trying to strike a deal. Now the two sides are back in Brussels, at it again.

British and European teams are struggling to craft a free-trade agreement that will allow the two sides to continue the orderly movement of goods and services across the English Channel.

If they fail to strike a deal, then Britain and Europe will enforce new customs duties, tariffs, border checks, and quotas on goods, increasing prices and fully ending the era of the free, frictionless trade.

They have 24 days to make a deal.

Specifically, the two sides are arguing over European access to fish in British waters, an emotional issue that taps into issues of sovereignty, even though the fisheries sector accounts for a tiny fraction of Britain's gross domestic product. 

There have been suggestions that European access to fish in British seas could be slowly reduced. Should the transition period be three years (a British proposal) or 10 years (a French proposal)? Stay tuned. 

The Europeans, too, are pressing to maintain a "level playing field," to stop Britain from undercutting worker protections or granting large state subsidies to British businesses, potentially giving the U.K. firms unfair advantages. 

The political press is reporting a "final push" this week, but in reality the sides have been pushing for a very long time.

Britain officially left the European Union in January, though it didn't quite leave. What it did was begin an 11-month transition period, which ends midnight on Dec. 31. The transition period that was granted to give the sides time to craft a trade deal, to avoid last-minute chaos and uncertainty. Numerous deadlines have come and gone.

How are things going? Not good.

"The news is very downbeat," Ireland's foreign secretary Simon Coveney told Ireland's state broadcaster RTE, who described the mood as "very gloomy."

The Irish minister said, "I'd like to be giving more positive news but at the moment these negotiations seem stalled, and the barriers to progress are still very much in place."

The British Foreign Office was a little less gloomy. Minister James Cleverly told the BBC the U.K. would keep negotiating "for as long as we have available time or until we get an agreement." He said negotiations "often go to the last minute of the last day."

"We are a global player, we are one of the biggest economies in the world, we are a real prize for many countries," Cleverly said. "I think if E.U. recognise this they will see that actually making a few small but significant concessions can get this deal done and that will be in their interest and in our interest."

Diplomats in Brussels, confronted with a spiraling series of crises, say that Brexit was long ago supplanted as the most burning issue they are facing. 

Nor is it even the trickiest negotiation they are facing in Brussels this week, amid acrimonious talks with two of the European Union's own members, Hungary and Poland. The two countries, whose commitment to democracy is increasingly shaky, have vetoed the entire $2 trillion E.U. budget because the other E.U. members want to make receiving funds conditional on adhering to the rule of law. 

Now E.U. ambassadors are receiving briefings almost every day from the bloc's top negotiator, Michel Barnier, a lanky former French politician who has sounded increasingly glum about the prospects for the talks.

They are fast running out of time, since any deal would need to be approved by E.U. leaders and a handful of parliaments before Dec. 31. 

"It was always going to go beyond any reasonable deadline," said one finger-drumming senior E.U. diplomat, who spoke on the condition of anonymity to detail frustrations with the British approach. 

E.U. officials familiar with the negotiations said that there was an agreement among themselves to halt talks Wednesday, regardless of their outcome, although such deadlines could easily be bargaining tactics. 

Another senior diplomat said Monday that differences remain on fisheries, rules about state aid to industries, and which body will enforce the deal - a summary that could easily have described most of the entire last year of negotiations. 

"If that sounds familiar to you, it is because there has been no decisive progress made so far," the diplomat said of the last few days of discussions, briefing reporters on the talks under ground rules of anonymity. 

Prime Minister Boris Johnson and European Commission President Ursula von der Leyen plan to speak Monday evening. A Saturday night conversation lasted an hour but proved fruitless in the end: they told their negotiators to keep negotiating. 

A downcast von der Leyen came out after the conversation to tell reporters that many differences remained. 

"Whoever has a crystal ball and is able to predict how first-of-their kind negotiations will unfold and conclude deserves a job as scriptwriter in the movie industry or to write novels," von der Leyen's spokesman, Eric Mamer, told reporters on Monday. 

Will Jennings, a professor of political science at the University of Southampton, said it was "very difficult" to know what was going on in negotiations as "both sides are giving briefings that tell different stories." 

He said it was a "strange political moment" because "it's incredibly salient for key decision-makers" but "the public seemed almost to have moved on." 

He said that there was a tendency, with E.U. and British politicians, "to take things to the brink and the last minute . . . like students handing in term papers" but it was also difficult to know whether the government really wants a deal. "The notions around Brexit are so wrapped up around sovereignty and taking back control" that there are "huge tensions around the integrity of Brexit and the grubby compromises of international negotiations." 

Jennings said Johnson wasn't merely talking tough to appease some of the hardcore Brexiteers in his own party, although they are applying pressure. "The government is led by key advocates of the Leave vote, not the softer side of the Brexit coin," he said. 

Brexiteers outside the party have been applying pressure, too. Nigel Farage, a media personality and former head of U.K. Independence Party, tweeted that there was "no reasonable negotiation on offer," as he disparaged French President Emmanuel Macron.

"Either we cave to Barnier and Macron or walk away," Farage said.