The British armed forces intercepted a Russian shadow fleet oil tanker attempting to pass through the English Channel overnight, Sir Keir Starmer confirmed.
In a statement on X, the Prime Minister said he had "directed our Armed Forces" to "intercept" the oil tanker.
He described the operation as "successful" and "yet another blow to Russia".
Sir Keir wrote: "In the early hours of this morning, I directed our Armed Forces to intercept a shadow fleet oil tanker attempting to pass through the English Channel.
"This successful operation delivers yet another blow to Russia and reminds those fueling Putin's war in Ukraine that we will not let them hide.
"I want to thank those involved, including our Armed Forces and law enforcement officers who keep this country safe 24 hours a day, 365 days a year."
The operation took place in the early hours of this morning, the Ministry of Defence revealed, which lasted six hours.
Royal Marine Commandos and National Crime Agency agents boarded the vessel, called Smyrtos, in the Channel.
The Prime Minister posted on X this morning confirming the operation had taken place
|X / KEIR STARMER
The vessel will now be held and monitored off the south coast as investigations take place.
Newly-appointed Defence Secretary Dan Jarvis said: "Operations like this require skill, professionalism and courage. I pay tribute to our Armed Forces personnel and all those involved.
"Russia relies on its shadow fleet to fund their conflict in Ukraine and our interdiction delivers a blow to Putin’s illegal war.
The operation was supported by Chinooks, Merlin Mk4 and Wildcat helicopters; an RAF P-8 aircraft; as well as HMS Sutherland and HMS Ledbury.
LATEST DEVELOPMENTS
The operation was supported by a host of military airpower, such as Chinook, Merlin Mk4 and Wildcat helicopters, an RAF P-8 aircraft
|GETTY
The MoD confirmed the operation was the "first UK-led operation of its kind" after Sir Keir agreed to the military and law enforcement boarding shadow fleet vessels.
Russia's shadow fleet of oil tankers attempts to evade sanctions imposed on its exports by having obscure ownership structures.
These fleets are responsible for carrying 75 per cent of Russia's sanctioned oil, with the shadow fleet boasting over 700 vessels.
It provides a critical lifeline for Russia's war chest.
The UK has already sanctioned more than 500 of these vessels, with the MoD saying it is "working".
Russia's oil and gas revenues fell by 24 per cent year-on-year in 2025, the MoD said.
In the first quarter of 2025, vessels sanctioned by the UK reduced the amount of oil they were carrying by $1.6billion.
Earlier this week, Labour's senior defence politicians walked out en masse.
John Healey, Al Carns and Pamela Nash all resigned, citing issues with how the Government is handling defence planning and funding.
Mr Healey said in his resignation letter the Prime Minister had been "unable and the Treasury has been unwilling to commit the resources that the nation needs to defend the country at this time of rising threats".
Mr Carns, the ex-veterans minister, accused Sir Keir of "asking our Armed Forces to operate in a more dangerous world on a budget written for a calmer one".
Mr Healey's Parliamentary Private Secretary, Ms Nash, also quit and said Labour "must do better".
Our Standards: The GB News Editorial Charter