Bosses are understood to be keen to emphasise that the postal service is at an inflection point as it pushes through a turnaround plan for its struggling letters business. Insiders pointed to the company's strongest Christmas performance in four years, as well as an ongoing review by Ofcom into its regulatory requirement to deliver letters six days a week. Royal Mail's performance would likely improve if the watchdog agrees on money saving changes. One source said Martin Seidenberg, IDS's chief executive, was "reasonably calm" about the company's prospects in the face of the shock takeover bid. Mr Kretinsky is already the largest shareholder in IDS with a holding of 27.5pc through his company EP Group. But his efforts to take full control of the business are likely to prove controversial given Royal Mail's critical role in British life.