In recent years the Courts have seen increasing use by claimants in multi party actions using a single claim form in some instances to start actions sometimes involving 1000’s of claimants. There has been come debate about whether this is permitted under the CPR. Caytons acted in this case where the relevant CPR provisions were tested by the Court of Appeal. Peter Mellett reviews the decision here and other recent cases on this point which is of importance in the context of group litigation claims generally.