The open revolt among rugby's players and coaching staff against plans to extend the Aviva Premiership season to 10 months has deepened, with one recent England international labelling the plan "unsustainable madness".
Last week, The Mail on Sunday revealed the anger felt by players, who could be expected to play almost year-round rugby from 2019-20 under Premiership Rugby's plans.
Players union chairman Christian Day is demanding to meet Premiership Rugby bosses to seek assurances over compulsory rest periods, but has so far been unable to secure a face-to-face meeting.
Day has refused to rule out strike action, while Bath rugby director and former All Blacks captain Todd Blackadder has become the latest coach to slam the proposals as unworkable.
Alex Corbisiero, the former England and Lions star, added his voice to the row, saying on his NBC Scrum Down podcast: "I am a big fan of Premiership Rugby, but my honest opinion is that this is a mistake.
"I don't think it is sustainable or workable. I think it is kind of madness to have an 11-month season, where internationals especially are expected to be playing again six or seven weeks after their last test, if there are to be no internationals missing Premiership games.
"We're supposed to have a mandatory five weeks off. I thought then they'll have breaks during the season, which will accumulate to five, but this is madness as well, because during the season, it is very hard to take proper time off.
"This needs to be calmly addressed around the table. The Rugby Players Association need to be able to sit in front of Premiership Rugby and voice their concerns - they need to draw a line in the sand.
"Christian Day said he hopes it never comes to strikes. I never want to see players strike,
"I'd love to see things worked out, but if this is an issue, which is not going to budge, I would fully support players striking, and doing what they need to get this point across to Premiership Rugby and World Rugby too."
Damian Hopley, the chief executive of the Rugby Players Association, signed off plans to align the northern and southern hemisphere, following World Rugby talks in San Francisco in January.
But Hopley has refused to comment on Premiership Rugby's plans, so it is unclear if he is aware of their plans to extend the season and leave some international players potentially facing 49 fixtures in a year.
Currently, players are not allowed to play more than 32 games a season to prevent intolerable stress on their bodies in one of the most physically demanding sports, with a minimum five-week rest period between seasons.
But the latest proposals to extend the northern hemisphere domestic season appear to fly in the face of hard-fought historic concessions made by clubs to player welfare.
England and Northampton star Courtney Lawes said: "The season already feels pretty long as it is.
"Pre-season is a very important time and you can make a lot of headway. Normally, the better your pre-season is, the better season you have.
"It's very important to get your body in the shape it needs to be in. It's going to be incredibly hard, if we're playing 11 months a year [including international tours].
"We probably won't get a pre-season at all.'