Are you talking about "Juzgados de Violencia Sobre la Mujer" or "Organic Act of Protection Measures against Gender Violence" or what are you lamenting? What law exactly and how is it unconstitutional?

If you're talking about that "gendered violence" gets different penalties compared to just "general violence", I think that's less about "different prison terms for men and women" but again, maybe you're talking about something else?