It's all of Europe
Recently they standardized Radio Comm Failure procedures in Europe. This included the 7 minutes of maintaining the last assigned speed and level.
Additionally, some member states specify that failure to comply may result in the cost of interception being charged to the PIC or Airline concerned.
Reference "Regional Supplementary Procedures, DOC 7030/4-EUR, Part 1, Rules of the Air, Air Traffic Services and Search and Rescue."