PARIS (Reuters) -France will ask the European Union to start legal action against Britain if it fails to issue more fishing licences by a Friday deadline set by the European Commission, a French minister said.

       Clement Beaune, the junior European Affairs Minister, also accused British Prime Minister Boris Johnson of trying unsuccessfully to isolate France in the dispute over post-Brexit fishing licences for French fishermen.

       France is still waiting for Britain to approve nearly 100 licences for its fishermen to operate in UK teritorial waters, Beaune told France Info radio.

       "If Britain today gives a few dozen extra licences as a token of goodwill... we will take that into account," he said, adding that if the deadlock persists, France will ask the Commission at the weekend to announce the start of legal action.

       Britain and the EU agreed to set up a licensing system to grant fishing vessels access to each other's waters when Britain left the bloc. But France says it has not been given the full number it is due, while Britain says only those lacking the correct documentation have not been granted.

       Fishing represents a tiny share of both the French and British economies, but it is politically sensitive.

       "Boris Johnson told himself he could isolate the French. We have re-mobilised (the Europeans) so that the deal is respected," Beaune said.

       Johnson's spokesman told reporters on Thursday that Britain never set a deadline for resolving the issue, a comment Beaune said was "not a sign of trust".

       French Seas Minister Annick Girardin said on Thursday that France would urge the EU Commission to take the matter for arbitration by a committee of British and EU representatives that oversees the implementation of the Brexit trade agreement.

       If that failed, France would push for the Commission to launch litigation proceedings, a move the minister said would take time.

       (Reporting by Dominique Vidalon, editing by Gareth Jones)