Tuilagi to write to Cameron
Manu Tuilagi will write to David Cameron to apologise for his prank on the Prime Minister.
Tuilagi gave Cameron 'bunny ears' while stood behind the him for a photo as the British and Irish Lions gathered at Downing Street.
The Leicester centre made the gesture as a group of players and management posed for the photo at the function to honour the Lions' 2-1 series victory over Australia.
The 22-year-old subsequently apologised on Twitter.
Former England hooker Brian Moore branded Tuilagi a "complete and utter prat", while his T igers coach Richard Cockerill described the actions as "daft".
"He has been a bit daft. He has made an error of judgement," Cockerill told BBC Radio Leicester.
"He should know better. He is old enough and wise enough to know he shouldn't have done it.
"We have reminded him of his responsibility and he has apologised on Twitter and he is writing to the Prime Minister to apologise if there was any offence taken.
"He probably thinks he is still at school messing about with his mates. There is a quality to that but also there is a time and a place."
Moore insisted the player 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.
Ian Ritchie, the chief executive of the RFU, predicted England head coach Stuart Lancaster would "have some words" with Tuilagi.
He added on Sky Sports News: "Recognise it for what it is, not a good thing to do, apologise for it and then we need to make sure that those sort of things don't occur again."
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!