"After listening to the issues raised by many of the players, we need to be very careful that we balance the commercial needs of the game, with the player welfare needs and ensure the quality and integrity of matches meets expectations," Read said.
"Fans want to see meaningful games; they don't want to see fatigued players playing a reduced quality of rugby as part of a money-driven, weakened competition that doesn't work for the players and clubs.
"With new technologies, new broadcast deals and new money coming into the sport, this is a crucial moment for rugby and one that many players are generally excited about. However, we have to make sure that the integrity of the game and welfare of the players is protected."
Nearly 40 players, including captains from a large contingent of the world's 10 top rugby nations, spoke on a recent conference call and are united in their concerns about the proposed format, including:
* Player load challenges around multiple top-level test matches across different countries and time-zones over consecutive weeks
* Increased long-haul travel in short time frames
* A lack of real opportunities for Tier Two nations to progress
* Increased conflicts between country v club demands and Regulation 9 release periods (nations being able to select their top players)
* Potential impact on the Rugby World Cup and Lions tours
* The long-term quality and integrity of the international game
Touching on World Rugby's consultation, or lack of, with the players, the IRPA statement made mention of "inconsistent engagement" – effectively code for little or no engagement.
IRPA president Sexton, Ireland's first five-eighth, said: "While players gave this idea a cautious welcome when we met at the end of last year, it now seems like a commercial deal on the future of the game is being negotiated at a rapid pace with little consideration given to the important points we raised with World Rugby in November.
"The issue of player load has never been so topical, however it needs to be properly understood. To suggest that players can play five incredibly high-level test matches in consecutive weeks in November is out of touch and shows little understanding of the physical strain this brings."
Samoa captain and player council member Chris Vui said: "For countries in this bracket and for Pacific Islanders in particular, our biggest issue has always been the 'club versus country' factor. We feel that a 12-year deal is not workable, particularly when it presents no hope of advancement during that period.
"This will have a dangerous knock-on effect of luring senior players away from their countries and more towards the clubs, which is the exact opposite of what we're all trying to achieve."
New Zealand Rugby boss Steve Tew was asked to comment on the proposed new league, but told the Herald NZR was not in a position to discuss any details..
"We continue to work very hard on a number of iterations for the future of the international playing calendar, but we are not in a position to discuss any of the detail at this stage. We will share more detail when we are able to," Tew said.