Tackling in children's rugby should be banned to prevent potentially devastating head injuries, a group of academics at British universities said on Friday, calling for government intervention on the issue.
It comes as a group of ex-professionals pursue legal action against a number of the sport's governing bodies for alleged negligence over concussion-related health problems.
Academics from Oxford Brookes, Newcastle and Winchester universities have written an open letter to all four chief medical officers in the UK calling for an end to tackling for school-aged children.
"Concern about injuries and traumatic brain injury in youth sport is of growing international concern, including in rugby union and rugby league," the letter said.
It points to efforts in the United States and Britain to ban or limit heading of the ball in football.
The letter refers to research by the Rugby Football Union (RFU) that they say highlights the lack of evidence for any "discernible physical health benefits" from full contact rugby compared with non-contact forms of the game.
"It is now well-established that young players under the age of 18 are particularly vulnerable to concussive injuries because of the maturing and the dynamic neurophysiological state of the adolescent brain," the letter said.
"The situation whereby the RFU determine the rules of play for children including in schools cannot continue," the academics added.
"We are concerned that in failing to act to protect children from the tackle in the school game and by allowing the sport's governing bodies to decide what, if any, information to collect, the British government is exposing children to significant risk."
A group of nine former professional players, including England's 2003 World Cup winning hooker Steve Thompson, are involved in a lawsuit against the game's authorities.
A pre-action letter of claim was on Thursday delivered to World Rugby, the RFU and the Welsh Rugby Union.
Oxford Brookes lecturer in sport and coaching science Adam White said urgent action was necessary to protect youngsters playing the game.
"Over the last few weeks we have heard the terrible news of ex-professional players who are suffering with the effects of concussions and sub-concussions on their brains," he said.
"We must now do everything we can to protect our children from suffering from the same mistakes."
There are also concerns over the high rate of dementia suffered by former footballers.
Restrictions have been put in place to stop children aged 11 and under heading footballs during training in England, Scotland and Northern Ireland.
However, there is a growing body of present and former footballers arguing that the age limit should be raised to 16.