Russia plotted undersea sabotage of UK cables

[Single-source reporting; allegations are attributed to unnamed officials and experts with no independent public confirmation available.]

Officials said Moscow’s GUGI plotted to sabotage undersea communications cables using deep‑sea submersibles in an operation foiled this month. Experts warned the episode exposed gaps in Britain’s ability to detect and deter attacks on fibre links that carry global internet traffic.

GUGI submersibles implicated

Two Western officials told investigators the operation was carried out by the Russian navy’s Main Directorate of Deep‑Sea Research, known as GUGI, and involved submersible vehicles deployed at depth. Officials said the attempt was intercepted before any damage to cables was reported.

Experts said the UK was "woefully" short of options to prevent or repair hostile interference on the ocean floor, citing limited surveillance and a small pool of specialised repair vessels. Officials and private‑sector specialists are assessing whether existing monitoring networks can detect covert submersible activity at commercial cable routes.

Governments and telecom operators are reviewing contingency plans for rerouting traffic and speeding repairs, officials said. Investigations are ongoing; officials did not provide a timetable for further public updates but said inquiries remain active in the days after September 11, 2026.