The Progressive Rugby member said while it’s accepted rugby will never be safe, the failure to reduce the playing and training load on the players demonstrated that claims player welfare was the number one priority was lip service.
Thompson, 45, who has no memory of the RWC2003 and has been diagnosed with early onset dementia and probable chronic traumatic encephalopathy (CTE), a brain disease thought to be caused by repetitive brain rattling from impacts to the head and body.
The father-of-four made the comments on ITV’s Good Morning Britain, when asked whether rugby could ever be a safe sport.
“It [rugby] is not gonna be a safe sport,” he said.
“But when it comes to the CTE aspect of it and the repetitive head injuries, they are coming from the training as well,” and pointed out the introduction of a new World Club Cup will stretch an already congested calendar to breaking point.
“They say that looking after the players is their number one priority, but they are just about putting another world tournament [together] for clubs,” he said.
“Players are going to be playing all year round, they are going to be training all year round and that's where it [the damage] happens.”
Thompson, who won 73 England caps (2002-2011), noted rugby's current schedule was significantly longer than that of the NFL which stretches over 17 weeks plus up to four weeks in the play-offs and where coaches are only permitted to schedule 16 contact sessions each year.
“American football is on for three to four months and they are resting for the rest of the year,' Thompson said.
“That doesn't happen in rugby, they are just literally flogging the players until they fall apart.”
Thompson is one of 328 ex-players taking legal action against World Rugby, the RFU and Wales Rugby Union after suffering dementia symptoms in a group that includes his former international team-mates Phil Vickery and Mark Regan.
Ex-Wales stars Gavin Henson, Lenny Woodard and Ryan Jones have also joined the legal action.
The claimants are seeking damages as they argue World Rugby, the RFU and WRU were negligent and failed in their duty of care by not putting in place any reasonable measures to protect their health and safety. The legal claimants are seeking damages but also change in the sport they played to protect the players of today.