London has until December 31 to hammer out a free-trade deal with the EU, and fisheries remain one of the most contentious issues. While the EU wants to secure the decades-old quota system which allows European boats to operate in British waters, the UK wishes to make its waters more exclusive to British fishermen.

On Friday, British media reported that the Royal Navy was ready to deploy four warships to stop European fishing boats from illegally entering the UK waters in the English Channel after a ‘no-deal’ Brexit. The Ministry of Defence later confirmed the news, adding that it had put 14,000 military personnel on standby to support the government during “the EU transition” period over the winter.

Many online were baffled by the prospect of British vessels pointing their guns at ships belonging to their allies. Some even suggested this could end up with London getting “thrown out of NATO.”

“An attack on one NATO member is an attack on all. How is this going to work out?” a person wrote while ‘Rule Britannia’ memes were posted on Twitter, and #GunBoatDiplomacy and #CodWars were trending.

The latter hashtag was a throwback to a series of standoffs between the UK and Iceland over fishing rights between the late 1950s and the 1970s. The conflicts ended on terms more favorable to the Nordic nation. This prompted people to worry Britain would eventually “lose” this time, too.

“Can't wait for French fisherman to blockade Calais,” a person quipped on Twitter.

Some, however, argued that UK will have no choice but to protect its waters if it fails to come to terms with Brussels. People voiced this sentiment while replying to a tweet by Tory MP Tobias Ellwood, who said the “overstretched” Royal Navy should rather focus on deterring Russia and China.

“An ally would give us a FAIR deal. A 'deal' that requires us to be subject to their rules and laws in perpetuity is NOT an ally, as they overrule our sovereignty for their advantage,” a person wrote to Ellwood.

Others opined that “a NATO ally should not allow its fisherman to plunder our waters,” and that “deploying four craft to protect British jobs is absolutely fine in my book.”