This work presents a new strategy for dealing with blending requirements in the composite structures design. Firstly, new analytical expressions of blending constraints, in the polar parameters space, are derived. Secondly, a dedicated numerical strategy for the recovery of blended stacking sequences is presented. The proposed approach is implemented in the framework of the multi-scale two-level optimisation strategy (MS2LOS) for composite laminates design. The theoretical aspects of this work are supported by the application of the proposed methodology to a numerical benchmark taken from the literature. The results obtained by means of the MS2LOS based on the polar formalism outperform those reported in the literature.