The European Supervision Order (ESO) is a European Directive that is designed to reduce the need for pre-trial detention. It is an alternative option that allows non-resident defendants to be held under supervision by the state that they consent to.
This system was created because of the negative effects pre-trial detention has on non-resident defendants. By imprisoning a non-resident before trial, they stand to lose their jobs, family connections and may have to support themselves financially in a different country that they may not have any ties to.
The ESO is given to the member state the defendant chooses (the executing state) by the member state where they are being tried (the issuing state). It is the job of the issuing state to specify which extra provisions, found in article 8(2), they require in addition to the mandatory supervision measures in article 8(1). The executing state, upon receiving the ESO, must agree or disagree to the listed provisions and send it back to the issuing state within 20 days. If the executing state approves the ESO, the defendant is allowed to go to that country under strict supervision; however, the executing state also has the right to refuse the ESO, as detailed in article 15.
If the defendant violates any supervision measures in the executing state, it is the duty of the executing state to inform the issuing state and allow them to decide the consequences, set forth in Article 18(1). If the breach of supervision measures results in the issuing of an arrest warrant, then the defendant must be surrendered in accordance with the European Arrest Warrant Framework Decision.
With the recent development of Brexit, the fate of the ESO in the UK is uncertain. Parliament issued a statement expressing that the UK wished to maintain its police and security cooperation with the EU, despite its exit. They also indicated that they would have to relinquish some measures or agreements. Parliament assured that the Government will be wary of relinquishing less-known measures, such as the ESO, during negotiations with the EU, as it could undermine the effectiveness of other tools or measures that are high-priority. So, at the moment, it is unclear whether or not the ESO measure will remain in place in the United Kingdom. If relinquished, the UK will lose a portion of its police and security cooperation with the EU and gain the burden of having to pay to imprison non-residents before trial.