London Irish administrator Lee Manning says it is only "a matter of time" until the next Premiership club goes bust and that "radical change" is needed.
Saracens missed out on the chance to book a Champions Cup round of 16 home tie as Castres produced a stunning victory in London.
Tom Willis surged over for two tries as Saracens dispatched second-placed Bristol Bears in a 35-26 victory in the Gallagher Premiership on Saturday.
Bath inflicted a record Gallagher Premiership defeat on 14-man Saracens as they powered to a 68-10 victory at the Recreation Ground.
Saracens climbed up to third place after a comfortable victory over Northampton in the Gallagher Premiership.
A round-up of Saturday's Investec Champions Cup action, where Northampton and Saracens made winning starts but Exeter were beaten by Sharks in South Africa.
Six-try Bath powered their way to a bonus-point victory over Sale Sharks to round off the first block of Gallagher Premiership matches in style.
Alex Lozowski booted a penalty with the game's final kick as Saracens claimed a thrilling 37-35 Gallagher Premiership victory over Bristol at Ashton Gate.