UK regulator, the Competition and Markets Authority (CMA), has released a stinging review of the proposed merger between Vodafone UK and Three. But the famously tough watchdog has left the door open for approval of the £16.5 billion deal. Last week, the CMA released the initial findings of its in-depth review, saying that it will lead to price rises for customers and poor overall infrastructure investment. “The investigation has provisionally concluded that the merger would lead to price increases for tens of millions of mobile customers, or see customers get a reduced service, such as smaller data packages in their contracts,” the CMA said. “The CMA has particular concerns that higher bills, or reduced services, would negatively affect those customers least…