Government sources have hurled crude insults at France after a row over fishing rights forced two Navy ships to go to Jersey.
Newspapers and newsletters carried eyebrow-raising briefings from anonymous UK authorities in a spat over the Channel Island.
The dispute erupted after the Jersey government said French fishing boats must obtain a licence to fish in the island's waters under the post-Brexit UK-EU trade deal.
France has threatened to cut off Jersey's electricity supply and French fishing boats are protesting at St Helier port over the row.
Downing Street was diplomatic today, saying Boris Johnson had deployed the Navy ships only as a "precautionary measure".
But anonymous sources were a lot less peaceful - with one telling the Sun and the Daily Mail: “At least when the Germans invaded in World War 2 they kept the lights on."
Meanwhile a government official told Politico French President Emmanuel Macron has "small d*** energy."
The Channel Islands were occupied by the Nazis during the Second World War and, despite the anonymous claim, hundreds of islanders were arrested, imprisoned and deported.
The insults flew as tensions escalated today, with France despatching two patrol boats to Jersey in the dispute over fishing rights.
Agence France-Presse reported the two police vessels had been sent after Britain deployed a pair of Royal Navy vessels to the Channel Island.
Earlier, dozens of French fishing boats gathered off Jersey's capital, St Helier, amid fears they were preparing to blockade the harbour.
Jersey's external relations minister, Ian Gorst, said he would be speaking to the French fishermen in an attempt to defuse the worsening row.
"It's important that we respond to threats, but the answer to this solution is to continue to talk and diplomacy," he told BBC News.
HMS Severn and HMS Tamar, armed with machine guns and cannon, have been deployed by the UK to "monitor the situation".
Earlier this week, French maritime minister Annick Girardin said Paris would cut off electricity to Jersey - which gets 95% of its power supply from France - if the dispute was not resolved.
The French maritime authority for the Channel and the North Sea said the patrol boats Athos and Themis were being sent to the island "to ensure the protection of human life at sea".
A spokeswoman said they were being stationed to be in a position to intervene "as quickly as possible" if the situation worsens.
French MEP Stéphanie Yon-Courtin, a member of the EU fisheries committee, called on the people of Jersey and the UK Government to "understand that our fishermen need to carry on working".
"This situation is all the more sad because historically Jersey and the French fisherman have always had very cordial and pretty good relations for the past decade," she told the BBC.
"Some of Jersey's people need to understand, and Jersey's government and UK Government, have to to understand that our fishermen need to carry on working."
Asked if she supported the threat that power could be cut off to Jersey in the future, she added: "I'm just saying that at the last resort, if we don't have any other means to be understood, then we will have to consider that. We don't want to do that, I don't think it's good, I don't think it's good for anybody."
Jersey Fishermen's Association President Don Thompson said the "big question on everybody's lips right now is 'will our Government capitulate to that sort of tactic?"'
He told ITV's Good Morning Britain: "The French fishermen out there want conditions removed from their licences so that they can fish with no constraints in our waters, whilst our boats are subject to all sorts of conditions about how much they can catch, where they can go."
He warned it would be "grossly unfair" if the Government does "capitulate to that" and said such tactics might be used "again and again in the future".
He added: "They're not very happy fishermen down here this morning, suspecting that we probably will see our Government give in to that."
Labour's Shadow Defence Secretary John Healey backed the sending of gunboats, saying: “The threats on Jersey are completely unreasonable. The Navy’s experience in sensitive situations will help reassure residents and protect Britain’s broader national interests. The British Government must now get round the table with French colleagues and authorities in Jersey and sort this issue out."
