OBS_VALUE: According to The National Security and Investment Act 2021 (NSIA), came into force on January 4th 2022, mandatory notification is required for any “notifiable acquisitions” in 17 sensitive areas of the economy that could harm the UK's national security grounds. Transport-related services are one of the covered sectors. This allows the UK government to review and intervene in the transactions even after they have completed. More information here https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1044388/nsi-process-flowchart.pdfBefore the adoption of NSIA 2021, there was no obligation to notify transactions. However, according to the Enterprise Act 2002, the UK government can intervene in a M&A transaction involving a transfer of material influence (above 15% shareholding) on public interest grounds when certain criteria listed in section 58(1)-(2D) of the Enterprise Act are met.