By Muvija M and Andrew MacAskill
LONDON, April 28 (Reuters) - Prime Minister Keir Starmer's decision last month to let the British military board ships of Russia’s so‑called "shadow fleet" has had no clear impact on the number passing through UK waters, a Reuters analysis shows.
In the month after Starmer's March 25 threat, at least 98 Russian vessels subject to UK sanctions transited its waters, about the same as each of the last three months.
There has been no announcement of any boarding or detention
of the ships, which typically have an opaque ownership structure and can transport oil, grains and arms, often in support of Russia's war in Ukraine.
LSEG tracking data shows that 63 ships passed within 12 nautical miles of the coastline in the English Channel, the most direct route between the Baltic Sea and southern Europe.
Another 35 travelled through Britain's Exclusive Economic Zone, which extends up to 200 nautical miles from the coast, mainly around north Scotland.
'EMPTY THREAT' TO BOARD RUSSIAN TANKERS
"You have to quickly follow up with boardings or otherwise those vessels will conclude that it was an empty threat — and that is the regrettable situation we are in now," said Elisabeth Braw, a maritime security expert at the Washington‑based Atlantic Council.
Other European countries including France, Belgium and Sweden have in recent months boarded and detained Russian "shadow fleet" vessels.
Britain's Ministry of Defence did not respond to a request for comment on its relative inaction.
Once a fabled sea power, Britain's navy is the smallest it has been since the 17th century, yet its military is facing requests from allies to support operations in eastern Europe, the Arctic and the Middle East.
London has 544 vessels linked to Russia’s "shadow fleet" on its sanctions list.
The data suggested that at least 10 ships passing through had engaged in "spoofing" - turning off or manipulating their tracking systems - when crossing British waters.
The Kremlin says sanctions against its ships are illegal and called Britain's latest policy a "deeply hostile move" that could draw retaliation.
Analysts say the UK's lack of follow‑through reflects several challenges, including lack of a dedicated law‑enforcement coastguard — unlike France or Sweden — plus the legal and economic complications of dealing with so many ships.
(Editing by Kate Holton and Andrew Cawthorne)
