A flexible thermoplastic resin composition comprising in admixture a polyphenylene ether resin, from 10% by weight to 50% by weight of an elastomeric block copolymer based on the total weight of polyphenylene ether resin and elastomeric block copolymer wherein the elastomeric block copolymer comprises in admixture from 75% by weight to 25% by weight of a triblock copolymer having a hydrogenated structure of A-B-A' and correspondingly from 25% by weight to 75% by weight of a diblock copolymer having a hydrogenated structure of A-B, wherein A and A' are independently selected from polymerized vinyl aromatic hydrocarbon blocks and B is independently selected from an ethylene-alkylene block, from 1 to 30% by weight of a polyolefin based on the total weight of the composition, and from 1 to 25% by weight of a flame retardant plasticizer based on the total weight of the composition, said flame retardant plasticizer being a phosphate compound.