The 11,600 truckers that cross the Channel each day would also face burdensome new paperwork requirements | Jack Hill/Getty Images London racing to avoid Brexit driving license roadblock Once the UK leaves, mutual recognition of driver’s licenses will end — unless a special deal can be done.

The British government is hoping a five-decade old U.N. treaty can ensure its motorists still have access to EU roads post Brexit.

The U.K.’s departure from the bloc threatens to end the mutual recognition of driver’s licenses, a European Commission briefing pointed out this week. Although British officials say they are "confident" a deal can be sealed that would ensure drivers from both sides can still roam freely with only their local pass, the backup option involves London ratifying a 50-year old U.N. treaty by March 2019.

Even that would still pile on the paperwork for British motorists making the short run to Calais to stock up on wine, and pose a nightmare for car hire firms, hauliers and insurance companies.

Slides published this week from an internal briefing by Commission officials to country diplomats as part of the Article 50 working group at the Council promised an end to “mutual recognition of driving licences, vehicle registration documents and certificates of professional competence for drivers” if the U.K. leaves the bloc without a deal.

It is only sensible that we put contingency measures in place for all scenarios” — Department for Transport spokesperson

“Our aim is to reach an agreement with the EU for mutual licence recognition after Brexit,” a spokesperson for the Department for Transport (DfT) said. “Such a deal is in the interests of both sides and we remain confident.”

Alternatives involve scrolling back through the ream of international treaties inked before the U.K. joined the bloc.

The Commission slides moot the Geneva Convention on Road Traffic signed in 1949 as a fallback treaty, but Germany and four Central European countries aren’t signed up to that.

London is instead hoping a speedy adoption of the Vienna Convention on Road Traffic, signed but not ratified by the government of the day in 1968 as a replacement for the Geneva Convention for countries that were signed up to both.

“It is only sensible that we put contingency measures in place for all scenarios,” the DfT spokesperson said.

Ratification would allow U.K. license holders to drive within the bloc after Brexit — as long as they have an accompanying International Driving Permit (IDP), which comes at a cost of £5.50 in Britain and needs to be issued in advance of travel.

The U.K. has already kickstarted the process of ratifying the Vienna Convention to “facilitate international traffic,” according to a DfT policy memo signed off by Transport Secretary Chris Grayling in January.

But that will need to happen swiftly and depends on Westminster passing treaty provisions, including a system for issuing permits for things like truck trailers and horse-boxes. The draft Haulage Permits and Trailer Registration Bill was described by James Hookham, deputy chief executive of the Freight Transport Association (FTA), as the first piece of "no-deal Brexit" legislation tabled in parliament.

A DfT official said the government launched the first step in the ratification process February 7, with a total 21 sitting days of parliament needed before it is approved. Foreign Secretary Boris Johnson will then have to sign the document before posting it to the U.N.

It takes 12 months for the ratification to kick-in, leaving the government under pressure to get the document posted to the U.K. in the coming weeks ahead of its Brexit deadline of March 29, 2019.

Even if the government manages to pass the bill in time to deliver the complete paperwork, British motorists face the prospect of having to shell out for new IDP documents for the shuttle to the Continent.

The 11,600 truckers that cross the Channel each day would also face burdensome new paperwork requirements if a deal on mutual recognition can't be worked out. The DfT memo also notes that "there will be some costs [to the government] in relation to the provision of a new system for issuing IDPs" and for a separate registration system for trailers.

Truckers also face the prospect of losing their transit and cabotage rights. The fallback option for cross-Channel freight traffic is a quota system from the OECD that would lead to companies having to apply for limited traffic permits for the U.K. that would account for just 3 percent of the necessary volume, according to the FTA.

The absence of a deal on licenses would hit EU drivers as well as those in the U.K.

"Failure to recognise licences and trailer permits would cut both ways," said Hookham. "It's perfectly possible to remove a lot of the friction that will be there by reaching these agreements but we haven't got a lot of time."