A flame-retardant coating composition, which includes a cross-linked thermosetting polymer and a metal hydroxide. A precursor composition for use in preparing the flame retardant-coating is also presented, wherein the precursor composition includes a cross-linked thermosetting polymer varnish, a metal hydroxide, an alcohol, and water. A method for coating an article with a flame-retardant coating layer and articles incorporating the flame-retardant coating are also presented.