Russian President Dmitry Medvedev has called for rules to be put in place to allow customers in Russia to retain their mobile phone numbers after changing their mobile operator. The Russian government has been attempting to implement a service called Mobile Number Portability (MNP) for several years. In 2005 the country\'s Telecoms Ministry worked out rules for retaining mobile phone numbers and affirmed them in 2009. In 2010 Russia\'s Interregional Transit Telecom firm offered to become a special mediator to implement the MNP service. MTS, Vimpelcom and MegaFon, Russia\'s three largest mobile operators, are against implementing the service, citing cost. The Federal Antimonopoly Service says implementation of the measure is possible and has been striving to introduce it for over three years, its head Igor Artemyev told Medvedev at an Open Government meeting. \"We can simply use [state] power. Mobile operators\' costs will be minimal,\" Artemyev said.