By Will Stewart & Kieren Williams Russia has lashed out at Rishi Sunak’s recent meeting with Volodymyr Zelensky as the UK pledges more support for Ukraine. One of the most senior security figures in the Kremlin even raised the suggestion of using cluster munitions against the UK Prime Minister and his party during their trip to Kyiv. The brash threat was issued by former Russian president, Dmitry Medvedev, now Vladimir Putin’s deputy on the Kremlin’s security council. It came as Sunak was in Kyiv for a surprise visit to the Ukrainian capital. During the visit he announced a further £2.5billion…