Yvette Cooper says claim against Kremlin ‘deeply serious’ while Russia dismisses western ‘feeblemindedness’ Yvette Cooper says claim against Kremlin ‘deeply serious’ while Russia dismisses western ‘feeblemindedness’ The UK is mulling fresh sanctions against Moscow after pinning blame on the Kremlin for the poisoning of the Russian opposition leader Alexei Navalny, Yvette Cooper has suggested. The Foreign Office and four of the UK’s allies – Sweden, France, Germany and the Netherlands –