Cycling UK recommends that group rides should not exceed 15 riders.
Full details can be found at: www.cyclinguk.org/article/coronavirus-guidance-individual-cyclists-and-cycling-groups
The paragraph about insurance is of particular interest.
To comply with this guidance the following will need to be applied to our group rides:
!/. If the ride has more than 15 riders turning up separate groups of no more than 15 riders will need to be formed.
2/. These groups will be able to ride the same route and go to the same destination.
3/. Each group will need to be split into sub groups of no more than 6 riders [which we already do] for road safety reasons etc.
When up to 15 riders turn up for a ride which appears to be the norm lately we comply with this guidance.
The problem is if more than 15 riders turn up which has happened in the past the main groups formed would need to be treated as completely separate to comply, albeit riding the same route and going to the same destination.