Pressure has been ramped up on rugby administrators to establish a global playing calendar amid complaints that the season is too long and players risk burnout.
The International Rugby Players' Association (IRPA), the worldwide body for professional players, called for shifting the June Test match window to the last three weeks of July, beginning in 2016.
The move would see northern hemisphere club competitions starting a month later, allowing more of their domestic competitions to be played after the Christmas break, potentially providing improved player availability for Tests.
In the southern hemisphere, the change would do away with Super Rugby's month-long break and allow players an extended pre-season, something that has been sought for years.
Following a conference in Australia, IRPA chairman Damian Hopley said the 2016 timing was important as the 2015 World Cup in England would put significant pressure on the season structures of northern hemisphere leagues.
Mid-week rounds have already been mooted, potentially hurting spectator numbers, club revenues and negatively impacting on player welfare.
The proposals would also see the British and Irish Lions, from the 2017 series in New Zealand onwards, touring in a clear window after Super Rugby, allowing more chance for clubs to field full-strength teams, a criticism during the Lions' recent tour of Australia.
Existing windows for World Cup, Six Nations, Rugby Championship, November Tests and provincial competitions would not need any change.
IRPA is now asking SANZAR, Premiership Rugby, the French Rugby League, The Celtic League, the International Rugby Board and the Six Nations to come together and consider the potential benefits of the proposal.
All Blacks captain Richie McCaw said he was in favour of the changes.
"If the game's leaders give this idea, or a variation of it, serious consideration it could be a game-changer for professional rugby," he said.
"It would be fantastic to address this long-standing season structure debate once and for all, the players and the game would be so much better for it."
McCaw's sentiments were endorsed by Ireland and Lions playmaker Jonny Sexton.
"We see this initiative as beneficial for the global game," Sexton said.
"From a player perspective, we urge our leaders to get in a room together, take a positive attitude and see what can be done."
IRPA executive director Rob Nichol said it was "a rare opportunity for greater alignment of the season structures in the two hemispheres".
"It is essential we use these discussions to achieve positive change for players, supporters and commercial partners," he said.
All previous attempts to improve coordination of the global calendar have failed due to the demands of various interests in the game.
Traditionalists do not want showpiece events such as the Six Nations moved, Europe's powerful clubs oppose further disruption of their season, while the southern and northern hemispheres each want Test windows tailored to their needs.