What is holding up the Unified Patent Court?

A form of unified patent protection has been available in Europe since the 1970s, but enforcement remains purely a national matter. After many years' negotiation, an agreement was signed in February 2013 to create a pan-European court (the UPC), potentially affecting global litigation strategies. A constitutional complaint brought in Germany in 2017 has delayed the project and potentially presents an existential challenge, but more likely the issue is how much further delay it will cause. It remains entirely possible the UPC will start in Q1 2019 (before Brexit). In addition, for patentees such as pharmaceutical companies requiring broad geographic protection, another part of the new system, the unitary patent, would also mean a dramatic reduction in patent maintenance costs.