The UK government has proposed new legislation to strengthen the security of undersea telecommunications cables, introducing mandatory resilience obligations for operators, tougher criminal penalties for infrastructure damage and powers to direct cable providers and repair companies during national security incidents.

The proposals, published October 22 in a government White Paper, would modernize legislation dating to 1885. Subsea fibre-optic cables carry approximately 99% of the UK’s international data traffic, making their protection central to the country’s international Internet connectivity.

Operators would face enforceable security duties. Providers of subsea telecommunications infrastructure serving the UK would be required to identify and mitigate risks, prepare for security incidents, restore services as quickly as reasonably practicable and report security compromises to authorities. A designated regulator could impose penalties of up to £10 million or 10% of qualifying worldwide revenue, whichever is higher, for noncompliance.

The proposed framework would cover infrastructure within UK territorial waters, where cables converge toward landing stations and face concentrated maritime activity. Detailed requirements would be established through secondary legislation and codes of practice, leaving important implementation questions for operators.

Government intervention could extend to repair operations. A proposed national security direction power would allow the Secretary of State to instruct cable infrastructure providers and repair-service companies to take, or refrain from taking, specified actions when necessary to protect national security. Failure to comply could attract penalties of up to £17 million or 10% of global turnover, whichever is higher, alongside continuing daily penalties.

The White Paper also proposes criminal penalties of up to 14 years’ imprisonment for intentional interference, 10 years for reckless conduct and two years for gross negligence, with unlimited fines. The offences would address physical damage as well as certain forms of electronic interference and obstruction of repairs.

The government cited suspected hostile activity around subsea infrastructure, including Russian submarine operations, as a reason for updating existing protections. It also proposes controls on fibre-optic sensing technologies capable of detecting activity around cables but potentially exposing sensitive information.

Industry costs and operational readiness remain under consultation. The proposals raise practical questions about risk-management expenditure, security at cable landing points, repair-vessel availability and the division of responsibilities among infrastructure owners and service providers. The government is seeking cost information from affected organizations alongside responses to its 12-week public consultation.

The measures are not yet law. Their final scope, enforcement arrangements and operational requirements will depend on the consultation and subsequent legislation.