BRUSSELS, March 10 (Reuter) European Union ambassadors on Friday told the European Commission to draw up a list of potential retaliatory measures against Canada in reponse to Ottawa's "violent arrest" of a Spanish fishing vessel in international waters.

An EU source told Reuters the Commission had been instructed to present the list at the beginning of next week.

Separately, COREPER, the committee of permanent representatives, issued a strongly worded statement demanding the Spanish vessel be released immediately.

"The (EU) and its member states wish to express their strongest condemnation of such an illegal and totally unacceptable act," they said after an emergency meeting.

"The Europan Community and its member states are forced to reassess their relationship with Canada in the light of this deplorable situation and reserve their rights to take any action which they deem appropriate," they said.