We analyze, by means of a random phase approximation (RPA) calculation, the conditions under which a mixture of oppositely weakly charged polyelectrolytes can microsegregate in the neighborhood of a charged surface creating a layered structure. A number of stable layers can be formed if the surface is sufficiently strongly charged even at temperatures at which the bulk of the mixture is homogeneous. The wave-length of the induced concentration fluctuation is proportional to 1/f(1/2) near the microphase transition, where f is the charge density of the polyelectrolytes.