Lawyers for more than 185 players are suing rugby union’s governing bodies for negligence, claiming that playing the sport caused brain damage.
World Rugby, the Rugby Football Union (RFU) and the Welsh Rugby Union are accused of failing to “protect players from permanent injury”.
Among those named as claimants are World Cup winner Steve Thompson and former Wales player Alix Popham.
World Rugby said it was “driven by a passion to safeguard our players”. The RFU and WRU have both been approached for comment.
Thompson and Popham have been diagnosed with early onset dementia.
Ex-Wales captain Ryan Jones is also a claimant after recently revealing he has the same diagnosis.
Law firm Rylands Legal said: “This claim isn’t just about financial compensation; it is also about making the game safer and ensuring current and former players get tested, so that if they are suffering a brain injury, they can get the clinical help they need.
“The players we represent love the game. We aim to challenge the current perceptions of the governing bodies, to reach a point where they accept the connection between repetitive blows to the head and permanent neurological injury and to take steps to protect players and support those who are injured.”
In addition to the rugby union legal action, the lawyers are also representing 75 rugby league players “as part of a separate but similar potential claim against the Rugby Football League”, the code’s English governing body.
A World Rugby spokesperson said: “At this time, World Rugby has not been issued with a legal claim and therefore it would be inappropriate to comment until we have received and reviewed the details of any potential formal action being taken.
“We care deeply about all our players, including former players, and never stand still when it comes to welfare. Our strategies to prevent, identify and manage head injuries are driven by a passion to safeguard our players and are founded on the latest science, evidence and independent expert guidance.”
