The Brumbies have warned members the Super Rugby club could fold if crowds continue to decline.
It comes on the back of their second-lowest ever crowd when they held an Australian derby with Melbourne at GIO Stadium this month.
The Brumbies aim to almost triple that figure of 5283 for their next match against the Sunwolves on June 3.
But in an email sent to members, chief executive Michael Thomson and chairman Phil Thomson explained the dire predicament and pleaded for more support.
"We know you want rugby to thrive in this region and, in part, to achieve this, we need a successful side playing in front of big crowds," the email reads.
"The funds attendance at games enables us to invest back into our programs ... and without your support and those funds the Brumbies may no longer exist."
After the nightmare attendance against the Rebels, the Brumbies have drawn on three Canberra charities to help lift numbers.
If the Brumbies reach their targeted crowd of 15,000, they will donate $5000 to each organisation.
It would easily top their biggest crowd for the year (13,515), which came against arch rivals the NSW Waratahs.
Michael Thomson said on Wednesday the declining figures could be put down to the team's struggles on the field, troubles within Super Rugby and an ageing stadium in an inconvenient location.
He pointed to the history of sport in Canberra in hope of a quick turnaround.
"Scheduling is a challenge but if we play the right football, we play entertaining and continue to connect with our community we're confident people will come," Thomson said.
"If you look at the history of sporting teams in Canberra, sometimes they turn quickly and we're confident if we continue to do the right things people will come back."