A decade-long attempt to create a unitary patent and enforcing court across European states appeared finally dead last night when Germany’s highest federal court ruled that the decision to join it had been taken unconstitutionally. Following the UK's indication that it would not participate as planned, this means that two of the three required lead jurisdictions have pulled out. 

The Unified Patent Court, one arm of which had been intended to sit in London, was intended to resolve disputes arising from a proposed unitary patent system applying to 25 European nations. Although not formally an EU institution, it had been intended that the European Court of Justice (CJEU) handle appeals on questions of European law. It was on this ground that Downing Street ruled out UK participation, despite Boris Johnson's ratification of the enabling agreement while foreign secretary.

The latest blow arises from a private citizen's challenge to the German Federal Constitutional Court (Bundesverfassungsgericht). In a judgment published today, the court ruled that as accession to the court would amend the German constitution 'in substantive terms', the act of approval required a two thirds majority in the Bundestag. As this had not been achieved, Germany's ratification is void. 

IP specialists said that the court, which is already four years behind schedule, would find it hard to recover. 'This almost certainly means that the UPC is finished,' said Michael Edenborough QC, barrister at Serle Court Chambers.  

The Law Society said the decision creates an opportunity for the UK to step into the gap by investing in its own patent litigation system and by appointing more technically qualified judges.  

This could be achieved by using the money, and even the premises in Aldgate Tower, London, it would have provided for the UPC in order to give the UK the best chance to remain a highly favoured jurisdiction for the resolution of patent disputes. 

Simon Davis president, said: 'There is a crucially important window of opportunity to make this investment before the UPC is off and running. By increasing training, recruitment and by appointing more technically qualified judges to hear patent litigation matters, the UK could sustainably bolster its jurisdiction on the world stage.

'It is the availability of these judges – which has fallen recently – that is most crucial to a fast, high quality and reasonable cost system with which the UK can confidently expect to maintain a very substantial share of high value patent litigation.'