The UK government would oppose any attempt by Sunil Bharti Mittal to increase his stake in telecoms group BT, said a report. The position is based on the need to keep sovereign control over what officials describe as critical national infrastructure.

Mittal’s Bharti Enterprises bought a 24.5 per cent stake in BT in 2024 from French-Israeli billionaire Patrick Drahi and has since raised it to 24.95 per cent. Any move above the 25 per cent threshold requires government approval, which British officials have said they would block, according to a report in Financial Times. BT shares fell about 3 per cent on Thursday morning.

A British government figure told the financial daily that the stance is not about Bharti or India specifically, but about keeping critical national infrastructure under UK control. The official added that resilience and sovereign capability have a different threshold today than in previous generations. The government usually informs valued overseas investors of its position ahead of future investments to avoid embarrassment.

Any attempt by Bharti to increase its holding beyond 25 per cent would trigger a formal review under the National Security and Investment Act. Since acquiring the stake, Mittal has built a close relationship with BT chief executive Allison Kirkby and secured two board seats last year, the report added. People familiar with BT board discussions said Mittal has shown ambitions for the company and his investment in the UK telecoms operator.

Mittal has been a longstanding investor in the UK and partnered with the government in 2020 to take control of the failed space start-up OneWeb. His Airtel Africa group is exploring a London listing for its mobile money business after the Iran war disrupted its original plan to float in the Middle East.