Billionaire mining magnate Andrew Forrest and former Wallaby John Welborn have renewed calls for the ARU to facilitate a Brumbies takeover of the Rebels, saying the Western Force are simply too valuable to axe.
RugbyWA and the ARU will begin arbitration in Sydney on Monday, with the fate of the Force hanging in the balance.
The Force will argue the 'alignment' deal they signed with the ARU last year guarantees their future until the end of the current broadcast deal in 2020.
But the ARU will counter that argument by saying the broadcast landscape has now changed given the Super Rugby competition will be reduced from 18 to 15 teams next season.
The South African Rugby Union has already axed the Cheetahs and Kings but the Force have found some powerful allies in their fight for survival.
Forrest, who is valued at $4.8 billion, has pledged to do whatever it takes to ensure the Force survive.
And he is supporting a plan that is being devised to assist a Brumbies takeover of the Rebels.
It remains unclear exactly who is masterminding the plan, but Forrest says a Brumbies takeover makes the most sense.
Although the ARU have previously dismissed the idea, Forrest's support could change their tune.
Forrest believes the plan would allow the Brumbies to expand their sponsorship base into a much bigger market.
The proposal also includes a plan for a rugby academy in Melbourne to provide a player pathway to the Brumbies.
Welborn, who played for both the Force and Waratahs during his decorated career, wants to see the ARU retain all five franchises.
But if it truly is the case that the ARU can't support five teams, Welborn said the merger was the next best option.
"From the planet Mars an obvious solution ... would be to put the Brumbies together with the Rebels," said Welborn, who is good friends with Forrest.
"Canberra has commercial issues, and always have had. But they've had the best rugby program in Australia and are very successful on the field." - Jon Welborn.
"It's amazing to me to hear claims that no one from the ARU has actively engaged with any of the teams in relation to a merger.
"It's hard to see how any criteria would result in the Western Force not surviving.
"There's a far more important rugby footprint here in Western Australia than there is in Melbourne."
Force chief executive Mark Sinderberry is confident his franchise will win the arbitration hearing.
Sinderberry said the backing of Forrest made the Force's case for survival irresistible.
If the Force lose the arbitration hearing, Sinderberry said the franchise would explore its legal options.
The arbitration hearing is expected to go for about a week. A decision is expected to be made within 10 working days of its completion.