British Prime Minister Boris Johnson’s government is desperately trying to re-open trade routes to France after a day of cross-Channel political bartering failed to end the chaos at the U.K.’s busiest port. France shut down freight traffic from Dover in southeast England at midnight on Sunday because of fear over a faster-spreading mutant strain of Covid-19 that forced the U.K. government to impose a strict lockdown on London and surrounding areas. Spain and Portugal, meanwhile, are among more than 40 countries restricting flights and effectively isolating the U.K.

Johnson said on Monday he’d spoken with French President Emmanuel Macron and Transport Secretary Grant Shapps also held talks with his counterpart, but an agreement expected “within hours” didn’t materialize. At least 1,500 trucks bound for the continent are currently stuck.

The standoff comes as Brexit talks with the European Union intensify over fish, a politically sensitive issue over which France is playing hard ball. The EU rejected the U.K.’s latest concessions on quotas, two officials said on Tuesday.

Meanwhile, the pressure is mounting to end the turmoil at the border turmoil that is threatening Christmas food supplies during the busy festive period.

Officials are at odds over the type of test to use, two people familiar with the talks said. The French side is pushing for hauliers to take PCR tests, which give a result in between 24 and 48 hours, while the U.K. prefers lateral tests that are less accurate but take only about 15 minutes -and would ease the long line a lot faster Richard Ballantyne, who heads the British Ports Association, is hopeful there could be an exemption for freight drivers that would be combined with testing for Covid-19 at the border.

Brexit Warning

The search for a solution to keep goods flowing in and out of Britain comes after another taxing weekend for the U.K. at the end of a tumultuous year. A spike in coronavirus infections forced Johnson to backtrack on allowing people to spend the festive period together, while talks with the EU on a post-Brexit trade deal entered a critical phase.