However, according to Reuters, Křetínský is now modifying his original non-binding offer to take over the British postal giant. Any acquisition would be subject to scrutiny by the British government under national security regulations.

Shares in International Distributions Services (IDS) rose 24% to 265p on news of the offer. Royal Mail has faced a variety of problems in recent years, including postal staff strikes, cyber security breaches, regulatory fines from Ofcom for failing to meet delivery targets and the loss of its 360-year monopoly on parcel delivery from post offices.

Křetínský already owns a 27.5% stake in IDS and is actively investing in the UK, where he has acquired stakes in supermarket chain J Sainsbury and London football club West Ham United, among others.