I have participated in no recent discussions regarding fishing opportunities for UK fishermen in Libyan waters.
Fishing opportunities for European Fishermen in Third Country Waters are negotiated by the European Commission through a Fisheries Partnership Agreement. Under the Common Fisheries policy the European Commission has competency to represent the member states in this context.
Currently there is no Fisheries Partnership Agreement between Libya and the European Community and there are no plans to make one in the foreseeable future.
This would not prevent individual UK fishermen gaining access to Libyan waters under a private agreement with Libyan fishermen. There are no European or UK laws preventing this at present. However this would be a private business venture up to the fishermen involved, and would necessitate the agreement of the Libyan Government.