Owners will be powerless to release their UK-flagged vessels if they are seized in retaliatory action by Iran, a UK lawyer has warned.

A British warship deterred a potential detention of BP's 158,000-dwt suezmax British Heritage (built 2017) in the Strait of Hormuz overnight, in response to the UK's seizure of a Ukrainian VLCC, the 301,000-dwt Grace 1 (built 1997) in Gibraltar in a sanctions case.