The Kremlin has denounced British Foreign Secretary Boris Johnsons statement comparing the World Cup in Russia to the Olympics hosted by Nazi Germany as "utterly disgusting,” in an escalating war of words between Moscow and London over the poisoning of a former Russian spy. Sergei Skripal and his daughter were poisoned earlier this month with a military-grade nerve agent in the southwestern English town of Salisbury. They remain in a critical condition. British Prime Minister Theresa May has accused Russia of the first known offensive use of a nerve toxin in Europe since World War Two and expelled 23 Russians whom she said were spies working under diplomatic cover. Russia has repeatedly denied any involvement in the attack, and in a reciprocal gesture, expelled 23 British diplomats as well as closing the British Council in Russia. Johnson agreed Wednesday with a Labour lawmaker who had suggested that Russian President Vladimir Putin is going to use Russias World Cup "in the way Hitler used the 1936 Olympics", as a propaganda exercise. Putins spokesman Dmitry Peskov described it Thursday as "the utterly disgusting statement which is unworthy of a foreign minister of any country." He called Johnsons words "insulting and unacceptable." Putin has dismissed allegations of Moscows involvement as "drivel, rubbish, nonsense", while Foreign Minister Sergei Lavrov on Wednesday urged the British government to "respond calmly" to the Skripals attempted murder.