"With the increasing competition from multinational companies in the UK postal market, private investment in Royal Mail becomes crucial." It added that Royal Mail is an "important national asset that would benefit from being able to take a longer-term view." The group said: "As a committed long-term investor in the UK, EP Group recognizes the importance of the Royal Mail business to its various stakeholders, including employees, trade unions, customers and government, as the UK's sole designated universal service provider. "EP Group has submitted its non-binding indicative proposal to IDS with the interests of these important stakeholders in mind." EP Group has until May 15 to make a bid or walk away under UK takeover rules. Kretinsky, who is said to be known as the "Czech Sphinx," already has a raft of investments, including stakes in London football club West Ham United and supermarket giant Sainsbury's.