Ramped-up security checks at European airports, such as this one in Montpellier, France, were agreed before the Brexit referendum and apply to anyone entering the Schengen zone | Pascal Guyot/AFP via Getty Images Brexit Files Insight Airport ‘shambles’ leaves Brexiteers fuming Tabloids and politicians blame the EU for delays affecting British holidaymakers.

The summer story of the week for the British tabloids was the lengthy queues at some European airports as a result of tougher security checks. Holidaymakers have had to wait for hours to get through, with flight delays and missed departures the consequence.

"Shambles at EU airports. Holidaymakers queue for hours as Brussels imposes tough passport checks — and British families suffer most," exclaimed the Daily Mail, pitting the put-upon British traveler against overzealous Continental bureaucrats.

The week culminated with an anonymous minister claiming the checks had been brought in as a shot across U.K. bows ahead of Brexit. "One wonders if this isn't just subterfuge from EU member states, if they aren't just trying to give us a warning that this is something that's in store for us after Brexit,” the minister mused in the Telegraph. His suggestion — separate lanes for British passengers entering the U.K.

But does the Brexit warning theory stack up? In a word, no.

The beefed-up security checks were agreed before the referendum and so are not themselves connected with Brexit. Plus, they apply to anyone entering the Schengen zone, including citizens of the EU27. Brits heading for Mediterranean sun are disproportionately affected only because the country is outside the borderless travel area.

Also, it was a security conscious then home secretary — a certain Theresa May — who was highly supportive of the move at the time it was agreed. May told the U.K. parliament in February 2016, before Britain voted to leave the European Union, that the country had a strong interest in improving the security of the EU’s external borders.

“I will stress the need for the measure to cover systematic checks at airports and push for Schengen and non-Schengen states to be able to exchange immigration information,” she told MPs.

The European Commission’s deputy chief spokesperson pointed out Friday that member countries had “unanimously” called for the new EU rules in October 2015. "You cannot have on the one hand a joint request to have more checks and more controls in order to increase security, and then at the same time complain about longer waiting times, because one is clearly the price for the other,” said the spokesperson.

The airport chaos story is a foretaste of the much trickier border questions to be resolved in the Brexit talks — which resume in Brussels later this month. It is also a warning of the media backlash negotiators can expect if they fail to thrash out a workable deal.

This insight is from POLITICO's Brexit Files newsletter, a daily afternoon digest of the best coverage and analysis of Britain’s decision to leave the EU. Read today’s edition or subscribe here.