Former England hooker Brian Moore has branded Manu Tuilagi a "complete and utter prat" for his prank on David Cameron when the British and Irish Lions gathered at Downing Street on Monday afternoon.
Tuilagi gave Cameron 'bunny ears' while stood behind the Prime Minister as a group of players and management posed for a photo at the function to honour the Lions' 2-1 series victory over Australia.
The 22-year-old Leicester centre subsequently apologised on Twitter, but while Moore believes it was a foolish act, he insists he should be spared punishment by England's management.
"My real objection is it wasn't very inventive," Moore told talkSPORT.
"People are saying they are offended. Are they really offended, or is it more a case of Tuilagi being an absolute prat again and taking the attention away from his team-mates?
"He has been a complete and utter prat. He ought to grow up, it's as simple as that, but people saying they are offended, are they really offended?
"The authorities I'm sure will do what they should do and say, 'Manu, everyone thinks you are a two-year old, do you really want that? Now go away and grow up please'."
Using Twitter to express his remorse for the incident, Tuilagi said: "Apologies for messing around on Lions photo. No offence intended. Great Day at Downing Street. Thanks to Prime Minister for hosting us."
It is not the first time Tuilagi has been the centre of controversy - he was fined £3,000 by the Rugby Football Union for jumping from a ferry during England's World Cup campaign in New Zealand two years ago.
He was cautioned by police on that occasion and disciplined by then England coach Martin Johnson.
Following his latest prank, Tuilagi's team-mates reacted on social networking site Twitter.
Ben Youngs, a fellow British and Irish Lion, England and Tigers player, tweeted: "The man@Manutuilagi just couldn't stop himself."
The scrum-half later removed the tweet and posted a picture of himself posing outside 10 Downing Street.
Gloucester fly-half Freddie Burns tweeted: "Great bottle from Manu Tuilagi!