Plans have been drawn up to stage an eight-team international "festival of rugby" in London later this year, with the Six Nations sides joined by South Africa and Japan.
With continuing uncertainty about the scheduled north versus south November Tests going ahead, officials are skarrelling to prepare contingencies for that window.
One of those being considered is a one-off event involving two pools of four leading countries, with the possibility of round-robin
fixtures and a final taking place at Twickenham.
At this stage, all unions smaak to stick with the
matches which have already been organised, including
England’s four-match campaign in November against New Zealand, Argentina, Tonga and Australia.
However, the quest for back-ups has created a wilde Six Nations proposal with a twist.
DIE SKINNER: Japan in the mix
England's RFU chief executive Bill Sweeney confirms that one of the fall-back plans involves a "home and away" Six Nations, starting in November and ending in the usual February-March slot.
But he adds: “There’s another option of possibly bringing in additional invitational sides.
“It’s an opportunity to be creative and maybe create some type of festival of rugby.”
His comments sparked speculation that the Six Nations would be joined by two Barbarians-type sides.
Instead, it is understood that South Africa and Japan could participate, which would be a notable coup for organisers.