Import dependency. The UK government put it at 43.5% in 2025 and 43.8% in 2024: https://assets.publishing.service.gov.uk/media/69cd1451b5210...

> EDIT: maybe you meant the UK total primary energy? I feel like that's extending the boundary a bit far.

If we're talking about 'sovereign', is it too far? I think the history of conflict in the modern era, hot and cold, shows that your rivals' ability to disrupt your energy imports matters a lot.