The Brexit trade deal still leaves French fisherman facing a host of unknowns, warned the mayor of the major northern fishing port of Boulogne-sur-Mer on Friday.
British Prime Minister Boris Johnson said on Thursday, as he presented the last-ditch accord, that his country had agreed a "reasonable" five-and-half-year transition period with the EU over fisheries, longer than the three years Britain wanted but shorter than the 14 years the EU had originally asked for.
But Boulogne-sur-Mer Mayor Frederic Cuvillier said the agreement left much obscured.
"Relief for our fishermen, but what will be the impact on stocks? Who, for example, will be handling the controls? And over what time?" he told Europe 1 radio.
"The only certainty today is that we need to find, during the transition period, more deals within the deal."
Cuvillier's views were echoed by French politicians Loïg Chesnais-Girard and Herve Morin, whose responsibilities cover the Normandy region bordering the English Channel.
Chesnais-Girard and Morin issued a joint statement welcoming the fact that a Brexit "no-deal" had been averted, but also calling for a meeting with French Prime Minister Jean Castex to analyse more of the details.
French fishermen had lobbied President Emmanuel Macron not to give an inch over fishing rights, but his government dropped initial demands to maintain the status quo.
French Seas Minister Annick Girardin issued a statement to say the government would set up financial measures to help French fishermen affected by the Brexit trade accord.
There has also been discontent across the Channel, with Britain's fishing industry expressing disappointment that the deal did not represent more of a reduction in the access that the European bloc currently has to British waters.