Plaintiffs lawyers who obtained two settlements with BP PLC over the Deepwater Horizon oil spill have accused prominent attorneys Ted Frank and Darrell Palmer of filing appeals on behalf of objectors who aren’t legitimate class members.

In a $9.6 billion settlement that resolves economic damages caused by the 2010 spill, class counsel have moved to dismiss the appeal before the U.S. Court of Appeals for the Fifth Circuit, filed by Frank and Palmer on behalf of four objectors. Frank and Palmer have fired back, asserting that class counsel deserve to be sanctioned for improperly raising the class membership issue just days before a Nov. 4 oral argument.