Plans for a major new departure for rugby appear to have received a fatal blow.
World Rugby says it does not wish to explore 'the concept' of a 12-aside competition at this point.
The idea of a World 12s tournament - which received the backing of some big names - was floated in September.
A World Rugby spokesperson said that the sport was focused on work surrounding the development of 'a harmonious annual international calendar' involving discussions with various stakeholders.
The spokesperson continued: "This is a position endorsed by the World Rugby executive committee and professional game committee, which includes representatives from across the elite men's and women's game."
Domestic leagues are also thought to be opposed to the proposed tournament.
Organisers viewed the idea of a World 12s tournament as rugby's equivalent to cricket's Indian Premier League.
Players would be selected through an auction to represent eight franchised teams.
It was anticipated that 192 of the world's best players would be involved, and take part in the tournament over three weeks.
Plans suggested that the first tournament would be held in England next year.
World Cup-winning coaches Steve Hansen and Jake White were among its backers, with organisers saying it would generate some €290 million in revenue for the sport.
The tournament's chief executive Rowena Samarasinhe, however, refused to say that the idea was finished.
"World 12s has been, and continues to be, in regular contact with World Rugby.
"The challenges around the international calendar are well known. World 12s is a long-term project and will grow over the years.
"We are optimistic that, even within the restrictions posed by the current calendar, World 12s will be able to host a tournament in August 2022 that includes a number of the game's leading players, who will not be impacted by fixture clashes at that time."