New Zealand's traditional rugby rivals say the World Cup would be an empty tournament without the All Blacks.
Former players from South Africa, France and Australia are critical of comments by the head of the International Rugby Board, who says the All Blacks are not essential.
IRB chief executive Mike Miller was responding to suggestion by the New Zealand Rugby Union that may boycott the next tournament unless changes are made to its structure.
A major sticking point is the commercial rules blocking unions from using their own team sponsors during a World Cup.
Former Springbok skipper Wynand Claasen agrees with the NZRU taking issue over team sponsorship. He says the IRB is behind the times.
Jean-Pierre Rives, who captained France from 1978 - 1984, says New Zealand is the spirit of the game.
For him the idea of a World Cup without the All Blacks is laughable.
Former Wallaby Peter FitzSimons says it would not be a proper rugby world cup without the All Blacks.
''But on the other hand, international rugby survived without the Springboks for 26 years,'' he said.
However, all three are confident a solution will be found and the All Blacks will make the 2015 Rugby World Cup in England.
Former All Black Richard Loe says the IRB has tunnel vision.
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Sadness expressed
The man in charge of organising the next Rugby World Cup says it will be sad if the All Blacks do not attend.
England Rugby 2015 chief executive Paul Vaughan told Morning Report the event is bigger than just one team.
He said it is sad the threat distracts from the excellent job New Zealand has done of showcasing rugby to the world.
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