Kyle Sinckler will miss England's Six Nations opener against Scotland after being hit with a two-week ban for failing to respect the authority of the match official.
Tighthead Sinckler appeared before an online independent disciplinary panel after being cited for the incident which took place in Bristol's Premiership victory over Exeter on Saturday.
The 27-year-old Bears prop said to referee Karl Dickson "are you f****** serious?" after the official ruled there had been no foul play in a tackle by England colleague Luke Cowan-Dickie.
Sinckler and Dickson were team-mates at Harlequins before the latter took up refereeing.
Sinckler contested the charge but it was upheld. He is free to play again on February 9, making him available for England's second Six Nations fixture against Italy at Twickenham.
He apologised for the outburst straight after the game, admitting it was "not the example I want to be setting".
"While Kyle Sinckler accepted that he used foul language at the referee, he did not accept the conduct warranted a red card," the independent disciplinary panel said.
"The panel viewed the live recordings of the incident and were satisfied that his shout of 'are you f****** serious' was aggressive and directed at the referee."
It was also decided at the hearing that Dickson had already explained to Sinckler that he believed Cowan-Dickie had attempted to wrap his arms in the tackle, at which point the Bristol tighthead swore at the referee.
"The player was candid in his evidence as to why he had done so and regretted his actions," the panel said.
"The panel found that as his actions disrespected the authority of the referee it was in breach of a core value of rugby - respect of match officials - and warranted a red card.
"The panel determined that in all the circumstances it was a low entry point with no relevant mitigation. The sanction is a two-week ban."
France want England, Ireland to provide safety guarantees
France's government is demanding reassurances on safety from England and Ireland before allowing its national side to visit those countries during the Six Nations.
Only the Championship's opening fixture against Italy in Rome on February 6 has been approved by Sports Minister Roxana Maracineanu.
The French authorities have concerns over the soaring number of Covid-19 cases in the UK and Ireland and have already barred their clubs from taking part in European competition this month.
The Six Nations held talks in Paris on Tuesday and discussions will be ongoing as organisers attempt to convince the government that sufficient coronavirus protocols are in place.
It is highly unlikely the tournament would go ahead without France, who play Ireland at the Aviva Stadium on February 14 and England at Twickenham on March 13.
"We keep the first match," Maracineanu said. "On the other hand, against Ireland and England we absolutely need to have the necessary guarantees from these countries.
"There has to be proof that the other nations' virus framework respects the same requirements in terms of precaution. We expect the same thing from the other teams."