Brussels is calling Theresa May’s bluff on security.

In her Article 50 letter, the British prime minister warned European leaders that cooperation in the “fight against crime and terrorism” would be at risk if the two sides failed to reach a deal on Brexit.

Now the EU is fighting back with what it’s best at: bureaucracy.

On April 27, the European Parliament is expected to green-light a new agreement between Europol and Denmark, an EU country that elected in a 2015 referendum not to participate as full member in the bloc’s justice and home affairs policies.

The deal and its timing, say European diplomats, Commission officials and MEPs, was intended by the Commission to be a not-so-coded message to London: You can’t blackmail us on security.

Until recently, Denmark had direct search access to the agency’s databases, which contain information ranging from vehicle and gun registrations to the names of organized criminals, foreign fighters and suspected terrorists.

“The Danish deal will work because Denmark is a small country that seems to cooperate, but would not work for the U.K. situation which is very different” — Claude Moraes MEP

But after the referendum, a new agreement — with Denmark outside of Europol — had to be struck. One possibility would have been a deal that granted Copenhagen full or partial access to the database, according to officials involved in the negotiations. Such an agreement would have set a precedent that could have allowed the U.K. to get something similar.

Instead, the deal, struck this month, stipulates that six to eight Danish officers will be based permanently at Europol headquarters in The Hague, where they will process individual requests from Danish security services.

It would be difficult for Europol to strike a deal with the U.K. — which will no longer be a member of the EU after Brexit — that is better than the one it has with Denmark. And even the arrangement it has with Copenhagen is unlikely to be acceptable to London.

Officials say it was clear throughout the negotiations with Denmark that the Commission was seeking to avoid setting a precedent for the U.K.

The arrangement with Copenhagen would not work for a country as large and active in Europol as the U.K., according to Claude Moraes, the British Labour MEP who chairs the European Parliament’s Committee on Civil Liberties, Justice and Home Affairs.

“The Danish deal will work because Denmark is a small country that seems to cooperate, but would not work for the U.K. situation which is very different,” he said. “The levels are so much bigger when it comes to sharing information on foreign terrorist fighters or trafficking.”

Furthermore, the timing comes just before new regulations governing Europol take effect on May 1, allowing the European Commission to rebuff British requests for a similar deal, on the grounds that it was negotiated under rules that are no longer in force, according to officials involved in the negotiations.

“The Commission got rid of an easier solution and forced all into this race against time in order to have a deal negotiated under Europol’s old regulation,” a senior EU official said.

The Danes, officials say, were a victim of the forthcoming Brexit negotiations. “Brexit had an impact in the awareness of not creating precedents,” said Morten Helveg Petersen, a Danish member of the liberal ALDE party who negotiated the deal, calling the result obtained “generous” but “soon to be outdated.”

Representatives of the U.K. government in Brussels declined to comment.

Leaving the club

Using security as a bargaining chip has “backfired” for the U.K., said Moraes.

London “should have known that that was a very awkward, inadvisable strategy,” he added.

A deal between the U.K. and the EU would also be complicated by the fact that Europol operates under the jurisdiction of the European Court of Justice, which the British government is eager to be rid of.

“Brussels should not allow the U.K. to do cherry-picking when it comes to Europol,” said Max-Peter Ratzel, a former director of Europol. “When you leave a club, you cannot pretend to enjoy the benefits of membership without paying the membership fee.”

There is also no provision under Europol’s legal framework to grant access to its databases to countries that are not part of the EU.

The Danes too have objected to any possibility that a country that was not a member of the EU would be granted better access than Copenhagen. “It sounds implausible that a third country would have a better deal than the one on the table for Denmark right now,” said Petersen.

Too big to fail

In the end, however, it may be Brussels that ultimately folds. Security experts say cooperation between the EU and the U.K. is “too big to fail,” according to a report by the RAND Corporation, a think tank.

Unless an agreement is struck, Britan’s exit would strip Europol of one of its most important contributors. British security services would no longer have access to the agency’s databases, and U.K. Home Secretary Amber Rudd has said her country would also withdraw all its information from the databases.

“I would argue that Britain will play a fairly aggressive game when it comes to Europol" — Raffaello Pantucci, counterterrorism expert

According to Europol, the U.K. is among the top four contributors to the Europol Information System (EIS), its main database on crime. It is also the fifth largest user of the agency’s platform to exchange information, the Secure Information Exchange Network Application (SIENA).

Europol’s director, former MI5 intelligence analyst Rob Wainwright, has argued repeatedly before and since the Brexit vote that both the EU and the U.K. would benefit from maintaining cooperation on security. He estimates that 40 percent of all Europol cases have some level of British involvement. Home Secretary Rudd has said that the U.K. is “the largest contributor to Europol.”

“I would argue that Britain will play a fairly aggressive game when it comes to Europol,” said Raffaello Pantucci, counterterrorism expert at the Royal United Services Institute in London. “There will be no precedent valid for them, they will want access to the databases. You will see some compromises on the economic side but not on the security one. Let’s be honest: It is in everyone’s interests that this works as smoothly as possible.”