England World Cup winner Steve Thompson is among a group of former internationals planning legal action against rugby authorities over brain injuries, said Rylands, the law firm leading the case, on December 8.

Thompson, who says he doesn’t recall winning the 2003 World Cup, is part of the group, along with another ex-England player, Michael Lipman, and former Wales international Alix Popham.

The planned action is against World Rugby, the Rugby Football Union (RFU) and the Welsh Rugby Union (WRU), for “failure to protect [the claimants] from the risks caused by concussions”.

The players have also created 15 “commandments” which they feel World Rugby should adopt to make the game safer.

Thompson, Lipman and Popham are part of a test group of eight players, but Richard Boardman of Rylands said he is representing more than 100 players, whose ages range from their 20s to their 50s, many of whom show symptoms of neurological problems.

Boardman said he wanted World Rugby to make immediate changes to address the issue, a growing concern in many sports.

“The obvious first step is for World Rugby, the RFU and WRU to stop being in denial and acknowledge that there is a problem,” Boardman added.

Thompson, 42, was diagnosed with early onset dementia (EOD) and probable CTE (chronic traumatic encephalopathy) in November.

“I have no recollection of winning the World Cup in 2003, or of being in Australia for the tournament,” he said.

“Knowing what I know now, I wish that I had never turned professional. I went from training twice a week to training every day, sometimes twice a day.

“Many of those training sessions were contact sessions. It was not uncommon for me to be left dazed, seeing white spots and not knowing where I was for a few seconds. Sometimes, I would pass out completely. It was just an accepted part and parcel of training.”

Popham, 41, was diagnosed with traumatic brain injury, EOD and probable CTE in April. He said the diagnosis had turned his world upside down.

“We had an answer to why I was struggling so much, but my future looked bleak. Mel and I only married last year. We were hoping to have another child, too, but that’s just not going to be possible now,” he said.

Lipman, 40, was diagnosed with EOD and probable CTE three weeks ago.

“This is something I will be battling forever, and ultimately I won’t win,” he said.

Boardman said senior figures in the game had been discussing the issue of head injuries since at least 1975.

But he added: “Inexplicably, the game’s approach to concussions [has] become less progressive in the professional era, as evidenced by the three-week mandatory break following a concussion being reduced to just six days in 2011.

“Whilst health and safety has moved in the wrong direction, the professional game has become a game with increasing collisions as players get heavier, stronger and faster.”

Proposals to make the game safer include abolishing contracts that compel injured players to play in order to get paid and limiting the number of contact sessions permitted in training.