Recycled XLPE from cable manufacturing waste and end-of-life cables were mixed with virgin polypropylene (PP) in order to evaluate the potential to be used in new injection molded products. The influence of metal contaminations on the mechanical and thermal properties and how the blends could be stabilized in order to be recycled and give reliable properties over time were studied. The results show that blends of 25–50% XLPE in PP give good mechanical properties with retained or improved impact strength independent of the source of XLPE. Ageing at 105 °C for 6 months showed a more severe material degradation and loss of mechanical properties for blends that contained XLPE with end-of-life cable. Addition of metal deactivator proved to retain the mechanical properties for more than 8 months of ageing at 105 °C. Simulated recycling of 50% XLPE in PP stabilized with a metal deactivator, showed that mechanical properties were preserved.