Prime minister approves tougher action against shadow fleet of oil vessels attempting to evade sanctions

UK armed forces have been authorised to board Russian oil tankers in British waters, Downing Street has said, in an escalation against Moscow’s sanction-evading shadow fleet.

The Royal Navy has previously joined allies in action against the vessels. Last week it helped track a sanctioned Russian oil tanker in the Mediterranean which was then boarded by the French navy.

But the prime minister’s move will mean that British armed forces or law enforcement will be able to go further to tackle the fleet of often ageing tankers using false national flags or opaque ownership structures to export Russian crude oil while avoiding western sanctions.

More than 600 vessels have been targeted by sanctions from the EU, UK and US. The new rules would apply only to those sanctioned by the UK.