The Six Nations and Rugby Championship could introduce promotion and relegation as part of planned changes to the international game.
World Rugby has outlined plans for a new global competition and revealed that it wants to press for promotion and relegation to be introduced to the Six Nations and Rugby Championship.
Plans for the new tournament, which would incorporate the two existing championships, drew widespread criticism when they emerged last week.
Stars including reigning World Rugby Player of the Year Johnny Sexton voiced their concern about the welfare of athletes, while senior players from Fiji, Samoa and Tonga threatened to boycott this year's World Cup.
The latter threat came amid reports the new competition would initially be a closed shop of 12 countries, excluding the Pacific nations.
But World Rugby released a statement on Wednesday in a bid to clarify their proposals, including stressing that all nations will have a "potential pathway" into the tournament.
"Contrary to reports, our proposed competition provides opportunities for all teams to compete at the top level on merit, with promotion and relegation," read the statement.
"Under this model, the Pacific Islands and all teams outside the current Six Nations and The Rugby Championship would have a potential pathway.
"With the proposed model incorporating competitions that are not owned or run by World Rugby, not all unions are presently in favour of immediate promotion and relegation.
"We continue to consider the feedback, but remain absolutely committed to an eventual pathway for all."
Addressing concerns raised about player welfare, World Rugby added: "Player welfare is fundamental to our sport. Within the original proposal, players would play a maximum of 13 matches if their team reaches the final, compared to an average of between 12 and 14 Test matches presently. Most teams would play 11 matches."
The proposed 'Nations Championship' would begin in 2022 with the 12 teams from the Six Nations and a new six-team Rugby Championship playing each other once, at home or away.
The top two teams from each competition would then play cross-conference semi-finals, followed by a grand final.
Wednesday's explainer also revealed that the competition would run in every year except those including a World Cup, plus a truncated schedule during seasons containing a British and Irish Lions tour.
