The development took place in the backdrop of a deepening dispute between them over fishing on either side of the English Channel.
The French minister said in a statement that the fine was imposed as a result of an investigation into the boats as part of tightening controls in the channel.
“We are starting the investigation again,” Maritime Minister Anik Giradin told French radio network. So it will ban British fishing boats from some French ports from next week. He also said that he would stop the supply of energy to the islands of the Channel.
At the same time, Britain said that the threat appeared to be a violation of international law and that Paris would retaliate if it proceeded on it.
Britain said: “The threat from France is disappointing and unjustified and we do not expect the same from a close ally and partner.”
Tensions between London and Paris have escalated since Britain left the European Union.