The objective of this work is to examine the effect of a non-uniform distribution of the applied edge loads on their net critical value with reference to the title problem. This forms a sequel to an earlier work on uniaxial compression of plates without any in-plane restraint at lateral edges to suppress the Poisson effect. A rigorous superposition approach is employed for plane stress analysis of the loaded plate, and the resulting non-uniform in-plane stress field is fully accounted for in the subsequent stability analysis which is based on Galerkin's approach with a complete set of admissible functions. Pertinent results are presented to highlight the influence of various non-uniform distributions as well as an in-plane restraint at the lateral edges.