Wales international Mike Phillips is planning to take legal action against Bayonne following his sacking.
The 77-times capped scrum-half said he was "disappointed and frustrated" by the club's decision.
"As a result of discussions with my legal team in France I have now instructed them to issue proceedings against Aviron Bayonnais Rugby Club," he said in a statement.
Phillips, 31, was accused of turning up for training drunk.
Phillips appeared before the Bayonne board on Tuesday, 22 October, to answer allegations he turned up to a video analysis session under the influence of alcohol.
Two fellow players, New Zealand back row Dwayne Haare and fly-half Stephen Brett, also had to answer allegations at that meeting. They were fined but not suspended.
On 24 October, Phillips apologised in French to Bayonne fans "for this situation" on Twitter, adding: "I am behind the team wholeheartedly. Good luck."
Phillips joined Bayonne from Ospreys in 2011 and was under contract with the French Top 14 club until June 2014.
He added in the statement: "I am extremely disappointed and frustrated by the decision taken by Aviron Bayonnais Rugby Club to terminate my employment.
"I was also disappointed by the fact that I officially heard about my dismissal through an interview given in a French newspaper this morning.
"I wish to thank my team mates and the many friends I have made in the Basque Country for their help and kindness over the past two seasons.
"I will now wholeheartedly concentrate all my energy and efforts on training with Wales and try to earn a place in the match day squad to help Wales have a successful autumn campaign against South Africa, Australia, Argentina and Tonga."
Phillips is in coach Warren Gatland's Wales squad for the autumn internationals, the first of which is against South Africa on 9 November.