Why are manufacturers leaving China?

During the last decades Western companies followed a common supply chain sourcing strategy which consisted on driving production plants to countries with cheaper costs. Particularly China has long been seen as a potential destination for a company`s product manufacturing. However firms are moving away from this model of production rethinking their global footprints and leading to a global reallocation of manufacturing. Why is the “Made in China” model weakening? Which are the alternatives for sourcing manufacturing? Could Spain be seen as a potential manufacturing location for companies leaving China?