Under the Enterprise Act 2002, the Secretary of State for Business, Energy and Industrial Strategy has the power to intervene in mergers on public interest grounds relating to national security. This responsibility is discharged in a quasi-judicial capacity, which means that the Secretary of State must act, and be seen to act, in a scrupulously fair and impartial manner.
On 5 December 2019, acting on official advice, the Secretary of State issued a public intervention notice confirming that she is intervening in the merger on national security grounds.
The Competition and Markets Authority (CMA) is now required to investigate and prepare a report which they must submit to the Secretary of State by midnight on 2 March 2020.
See the related news story.