Today, O2 and Vodafone have officially launched their LTE services in the United Kingdom. However, Vodafone's LTE network is available only in London, while O2 offer's its 4G services across three cities - London, Leeds and Bradford at the moment. The 4G LTE networks across the UK is dominated by EE, which is currently offering 4G in 100 markets in the country. EE also has the government's...
Source: http://www.gsmarena.com/o2_and_vodafone_launch_4g_lte_networks_in_uk-news-6676.php