France fly-half Romain Ntamack says it is "totally incomprehensible" the terms of his suspension following a red card differed to the sanction for Ireland centre Garry Ringrose.

Ntamack returned to action in Les Bleus' 42-27 victory in Dublin last weekend after missing two Six Nations matches following his dismissal in the opening-round win against Wales.

Ringrose is available to feature in Ireland's championship finale in Italy on Saturday having sat out only one Test - the defeat against France - as punishment for his dismissal against Wales.

Ringrose was permitted to count a Leinster fixture - a game which he was unlikely to have featured in - as part of his ban but Ntamack was unable to include a match for his club Toulouse in his punishment.

"There is an injustice here, because I believe our case was also based around how one of the matches in my suspension I would play for Toulouse," the 25-year-old said before Saturday's game against Scotland.

"And when 10 days later the complete opposite [for Ringrose] is decided in contrast to what the commission told me, that is in every shape and form totally incomprehensible.

"I think we must start pounding our fist on the table because it is time these decisions going against us and costing us dearly stop."