The European Union’s Single-Use Plastics Directive includes a requirement for all single-use beverage containers to come with their caps attached by July 2024 to help ensure the caps are disposed of and recycled together with the rest of the pack. Even the UK is outside the EU most manufacturers are changing to tethered caps to meet the EU rules.
Cawston Press has always recommended putting the cap back on your rinsed and squashed empty carton, so the new tethered cap will just help with that. Putting the cap back on helps to reduce accidental littering and gets more plastic into the recycling stream