National Security and Investment Act

The National Security and Investment Act 2021 (NSIA) came into force on 4 January 2022, giving the UK Government the most expansive foreign investment screening powers it has held since nationalisation-era legislation. It applies to 17 sensitive sectors, including advanced materials, AI, civil nuclear, cryptographic authentication, data infrastructure and defence. Acquirers of entities active in these sectors must give mandatory notification to the Investment Security Unit within the Cabinet Office before completing a transaction; the government then has 30 working days to call in a deal for national security assessment, extendable to 75 working days for complex cases.

The Act's defining precedent is the Newport Wafer Fab case: the Secretary of state ordered Nexperia in November 2022 to divest 86% of the shares it had acquired in the Welsh chip fab on national security grounds tied to Nexperia's Chinese ownership, a divestment that completed a year later when Nexperia sold the plant to US-based Vishay Intertechnology for $177 million . NSIA has been exercised over 100 times since commencement, with most called-in transactions cleared subject to conditions rather than blocked outright.

In April 2026 Airbus signed a definitive agreement to acquire Ultra Cyber from Cobham, bringing Ministry of Defence sovereign cryptography and cyber-defence programme work under French-headquartered European ownership . Ultra Cyber sits directly in the cryptographic authentication sensitive sector, and its programmes are MoD-cleared, making the acquirer's status as a non-UK, EU-ally entity the deal's central NSIA question.