New EU Plant Health Regulations came into effect in December 2019. The UK operates under WTO obligations and will apply the EU Plant Health Regulation until the end of the Transition Period. Under certain circumstances, the UK also uses national measures to enhance or supplement the main biosecurity provisions in the EU Regulation. These national measures are only used to protect against pests or diseases that are not already established in the UK. Ash dieback no longer meets this criteria – it is well established and widely distributed, being present in every county. As such, there is no technical case and no purpose to retaining national measures against ash dieback. The main risk to ash now is from entry of new strains of ash dieback present in Asian countries but not Europe, as well as pests such as the emerald ash borer. To mitigate these threats, imports of ash from outside the EU will continue to be prohibited and specific measures against the Emerald Ash Borer (which is not present in the UK) are in place.
The implications of the changes are that trade in ash trees from the EU could potentially resume as well as trees being bought and sold within the UK. As currently there is no guaranteed disease-tolerant ash on the market, it is viewed that ash is not a sustainable planting choice.