Fishermen angry at skyrocketing oil prices on Friday blocked ports in north and north-west France including Calais, Le Havre and Boulogne-sur-Mer, disrupting cross-Channel ferry traffic for hours.
"This is not a true strike today, it's a warning shot," said Christian Dubois, who works out of the Channel port of Calais.
Alexis Maheut, president of the Upper Normandy regional fishermen's committee, said high oil prices were making work "impossible" for him and his colleagues.
"Diesel oil is one of our primary expenses after social charges, and when we know that the price of diesel oil has gone up 34 percent since the start of the year, it's not hard for us to see that we're in a tough spot," Maheut said.
The blockade lasted for about four hours, from 10:00am (0800 GMT) to 2:00pm (1200 GMT).
Some 100 fishermen who gathered in Boulogne-sur-Mer demanded that the center-right government allocate a 200-million-euro (248-million-dollar) aid package for the industry.
"Since February, no one has listened to us. The agriculture minister is an honest guy, but everything goes through Bercy (the finance ministry). We've been taken for a ride," said Pierre-Georges Dachicourt, head of the National Fishermen's Committee (CNP).
An inter-ministerial meeting on aid to fishermen to resolve the positions of the agriculture and finance ministries took place on Thursday, but sources said the finance ministry had yet to agree to several measures.
Agriculture Minister Herve Gaymard was due to meet with representatives of fishermen's organisations on Tuesday.
Oil prices hit all-time peaks of 50.47 dollars in out-of-hours deals in New York on Tuesday and 46.80 dollars in London.