An EU flag is seen outside British Parliament in London, Britain. Both sides remain apart on a post-Brexit deal, but are working to overcome differences on fishing rights in British territorial waters. File Photo by Neil Hall/EPA-EFE
Dec. 18 (UPI) -- British and European Union negotiators are trying to work through differences on Friday over fishing rights in Britain's territorial waters, in what one official said are the final few hours to reach an elusive post-Brexit trade deal.
EU chief negotiator Michel Barnier said the bloc won't back down from maintaining the right to sanction Britain if it decides to close territorial waters to EU fishermen after the transition period ends this month.
Britain has long argued that it should have sovereignty over its waters, including authority over who can use them for commercial purposes.
The issue is just one of several that have kept negotiators from agreeing to a broad trade agreement for Britain's post-Brexit existence. Britain left the EU in January but a transition period to iron out trade details for its future trade relationship with the alliance expires on Jan. 1.
Barnier said Friday there are just a "few hours" remaining to reach a deal, mainly because any agreement would need to clear necessary approvals on both sides before the transition ends in less than two weeks.
"If following a critical period of adjustment that is deemed necessary, if [Britain] then wants to cut access to these waters for European fishermen, at any given time, then the European Union also has to maintain its sovereign right to react or to compensate by adjusting the conditions for products, and especially fisheries products to the single market," Barnier said.
"And that is where we come up against one of the main hurdles of the negotiations at the moment, fisheries being part and parcel of the economic partnership."
European Commission President Ursula von der Leyen said in a statement Thursday night, after a call phone with British Prime Minister Boris Johnson, that the fishing issue remains "very challenging."
"We welcomed substantial progress on many issues," von der Leyen said. "However, big differences remain to be bridged, in particular on fisheries."
Johnson said Britain has made every effort to "accommodate reasonable EU requests" on "level playing field" issues, but argued that the bloc is asking for too much with the fishing rights.
"[Britain] could not accept a situation where it was the only sovereign country in the world not to be able to control access to its own waters for an extended period and to be faced with fisheries quotas which hugely disadvantaged its own industry," Johnson's office said in a statement.
"The EU's position in this area was simply not reasonable and if there was to be an agreement it needed to shift significantly."
Johnson did say Friday, however, that British negotiators will keep up negotiations.
"Obviously the U.K.'s position is always that we want to keeping talking if there's any chance of a deal," he said.