The Guinness PRO14 Rainbow Cup will be split into two separate tournaments after no solution was found that would allow the South African teams to enter the UK and Ireland.
The Sharks, Stormers, Lions and Bulls had been due to join the 12 PRO14 teams in a six-round competition, starting on Friday and culminating in a final on June 19.
Amid speculation that the tournament may not go ahead, organisers published fixture details for the opening three rounds earlier this month, although the schedule was dominated by derbies, with Irish, Welsh and South African sides not leaving their own country.
The intention had been for the South African franchises to travel north to Europe for rounds four to six, but logistical obstacles caused by the coronavirus pandemic mean they will now play amongst themselves in ‘Rainbow Cup SA’.
The existing PRO14 teams will proceed with their scheduled fixtures.
A PRO14 statement read: “All options for the South African teams to travel to Europe safely were explored and exhausted by the league, this is due to the heightened restrictions caused by South Africa’s presence on the red list of the territories involved.
“A wide stakeholder group, led by a working group between the tournament team at PRO14 Rugby and SA Rugby, produced a long list of various options for entry of the teams, base camps and high-standard medical protocols across the past four months to cater for different scenarios.
“In total, 12 venues across the UK, Ireland and Europe were considered as base camps for the South African teams to operate out of or to use as a quarantine destination before entering the UK and Ireland. SA Rugby also explored another four locations separate to this.
“Further, destinations in the Middle East were also explored as potential hosts for fixtures involving South African teams.”
It had been thought that the competition could pave the way for the South African franchises to join an expanded PRO14 on a more permanent basis.
“This decision will have no impact on the long-term partnership between PRO14 Rugby and SA Rugby and more details about those plans and league structure for the ground-breaking 2021-22 season onwards will be made public shortly,” added the statement.
Jurie Roux, CEO of SA Rugby, said: “This is a huge disappointment, but time had simply run out.”
A Scottish Rugby spokesperson commented: “While it is disappointing the Rainbow Cup cannot progress in its intended format, we would like to thank colleagues at PRO14 for all their efforts in developing and progressing this concept.
“Covid-19 has impacted sport at numerous levels and the safety of everyone in this pandemic must remain the priority.
“We look forward to the Rainbow Cup in its new, revised format and wish Edinburgh Rugby and Glasgow Warriors well in their up-coming matches.”