The Kremlin on Saturday denied a claim that former Russian spy Sergei Skripal wrote to Russian President Vladimir Putin asking to be pardoned and to be allowed to visit his home country. "The former Russian intelligence officer, who came to Britain in 2010 as part of a spy swap, regretted being a double agent and wanted to visit his family," his friend Vladimir Timoshkov said. He added that Skripal, who had known him since school, did not see himself as a 'traitor', as he had "sworn an oath to the Soviet Union," The Guardian reported. Last week, UK suspended 21 Russian diplomats back to Moscow after the former said that Russia was "highly responsible" for the poisoning attack. British Prime Minister Theresa May called the incident "a brazen attempt to murder innocent civilians on our soil." and has accused Russia for carrying out the attack. Russia has vehemently denied any responsibility for the incident, while Vladimir Chizhov, Russian ambassador to the EU, said that "from the legal point of view the Russian state had nothing against him [Skripal]". Retired military intelligence officer Skripal, 66, and his daughter, Yulia, 33, were found slumped on a bench in Salisbury city centre on March 4. However, they remain in a critical but stable condition in hospital. According to media reports, Skripal was convicted by the Russian government of passing secrets to UK's Secret Intelligence Service MI6 in 2004, but was given refuge in the UK in 2010 as part of a "spy swap." Russia's ambassador to the UK, Alexander Yakovenko sent well wishes to Skripal and his daughter on Friday, saying "he hoped for their recovery."