Cloisters is poised to split its civil and criminal teams.
Cloisters' criminal and civil groups held crisis talks last week and it is understood that the 15-strong criminal team will leave chambers.
But the team's destination has yet to be finalised. One option under discussion would create the UK's first criminal "super-set" through a tripartite merger with Cloisters' criminal team, Michael Mansfield QC's 14 Tooks Court and 2 Garden Court. The merged set would hold more than 100 tenants.
Cloisters' 50-tenant set has been undergoing a restructuring process for the past 18 months, which has seen senior clerk Michael Martin ousted and replaced by Vanessa Peters, a chambers director who has now also left with several tenants.
But a Cloisters spokesman says: "It would be wrong to describe this week's meetings as crisis meetings.
"All that is happening is that we are entering the final phase of a regeneration programme which is designed to ensure the best possible outcome for all of our present practitioners in today's market.
"We are confident that the present process will be completed before the beginning of September."
8 King's Bench Walk is also undergoing a period of upheaval.
Seven tenants are leaving to establish a new set. The chambers has lost 20 tenants in the past six months.
King's Bench Walk's senior clerk Marc Foss says: "We lost some people to a specialist family set [1 Pump Court] at the beginning of the year. We've also lost some members in Leeds."
But Foss says that despite the latest departures, who are all criminal practitioners, the set will continue to practise in its core areas of crime, immigration and housing.