Paris on Wednesday denounced as "totally unacceptable and inadmissible" decisions by the UK and Jersey to refuse fishing licences to the majority of French boats that had asked for one.
Government spokesperson Gabriel Attal told reporters they were "decisions that contravene the agreement that was signed in the context of Brexit".
"The French state will obviously stand by its fishermen in this discussion," he added.
His comments came hours after Jersey announced that it has declined to grant fishing licences to 75 French vessels.
Since Brexit took effect at the start of the year, French boats were allowed to continue to fish in Jersey waters under a temporary agreement.
But the local government is now calling time on that deal. It says those who have been refused a licence "must stop fishing in Jersey waters in 30 days' time".
While 75 vessels have been refused a licence, 64 have been granted one. A further 31 provisional licences -- valid until January 2022 -- have been issued to vessels that need to provide additional information to get permanent permission.
These add to the 47 permanent licences already issued by Jersey since the start of the year. Authorities reiterated they will "accept and consider further data and evidence" from unlicenced boats "as and when it is submitted".
Senator Ian Gorst, minister for external relations for Jersey, which like Guernsey is a semi-autonomous dependency of the British Crown, said in a statement that "Jersey has maintained a pragmatic, reasonable and evidence-based approach throughout, extending the transitional period on a number of occasions until now, despite not being required by the TCA (Trade and Cooperation Agreement) to do so".
"We're now in a position to ensure those boats which have fished these waters are able to continue doing so, and therefore it is time, next month, for our transitional arrangements to come to a close," he added.
At the beginning of May, dozens of Norman and Breton fishermen's boats had massed in the port of Saint-Hélier in Jersey to defend their right to continue fishing in these waters, causing London to send two patrol boats for a few hours.
This outburst led to the extension of the deadlines without changing anything in substance: European fleets will have to give up 25% of their catches in British waters at the end of a transition period running until June 2026.
Jersey's announcement comes with Paris and London at loggerheads over fishing rights since the UK's departure from the European Union, with France accusing the UK of failing to honour the Brexit agreement concerning fishing licences.
Dozens of French licences are set to expire.
The UK announced on Tuesday it would grant 12 additional licences — just about a quarter of the 47 new licences France had requested.
The post-Brexit agreement negotiated with the European Union provided that EU fishermen could continue to fish in certain British waters if they obtained a licence.
The licence would be granted if they could prove they were fishing there before.
In total, including the authorisations previously issued by London, 100 licences out of 175 have been granted, according to the French Ministry of the Sea.
"This is a new refusal by the British to apply the conditions of the Brexit agreement despite all the work undertaken together," said Annick Girardin, the French Minister for the Sea.
"I have only one watchword left: to obtain definitive licences for our fishermen as provided for in the agreement. French fishing must not be taken hostage by the British for political purposes.”
The minister is due to meet representatives from "professional organisations" concerned on Wednesday.
The European Commission said meanwhile that it takes note of the UK government's latest round of licences but "regrets that it has not been possible to bring this issue now to an end."
"We will ask the UK for full disclosure of their methodology and will continue to further engage in the interest of our fishermen and -women so that further licenses will be provided," it added.
Paris is still awaiting replies to 168 requests for definitive authorisations in Guernsey.