If aluminium or barium ions are added to an aqueous solution of sodium polystyrenesulfonate (NaPSS) the ions will induce coil shrinking. Once a critical limit of counterions per sulfonate groups is exceeded, aggregation and thereby precipitation of the polyelectrolyte chains sets in. Neutron scattering experiments on deuterated NaPSS are suggested to get information about the change in morphology of shrinking PSS chains, induced by the respective cations close to the phase boundary. The results are also expected to broaden our knowledge on the impact of specifically interacting metal cations on the shape of polyelectrolyte chains in dilute solutions.