The UK's Competition and Markets Authority (CMA) has initiated an in-depth investigation into the proposed £15 billion merger between Vodafone and Three, two of the country's leading mobile network providers. This move comes amid concerns that the merger could potentially lead to higher prices for consumers. The decision to refer the deal for a more thorough review has been widely reported and confirms the regulatory challenges facing the merger. The investigation aims to assess the implications of the merger on competition within the UK's mobile telephony market.