Poisoned former double agent Sergei Skripal asked Vladimir Putin to be pardoned and requested he be allowed to visit Russia, according to a friend.
The 66-year-old, who, along with his daughter Yulia, is in a critical condition following a nerve agent attack, wrote to the Russian president in a bid for leniency, Vladimir Timoshkov said.
He told the BBC that Mr Skripal, who came to Britain in 2010 as part of a spy swap, regretted being a double agent.
Mr Skripal was also keen to be reunited with his family.
The attempted assassination of the spy on March 4 in Salisbury is continuing to cause a diplomatic crisis between Russia and Britain.
According to Mr Timoshkov, his friend, who he had known since school, did not see himself as a traitor as he had sworn an oath to the Soviet Union.
"Many people shunned him. His classmates felt he had betrayed the Motherland," he said.
"In 2012 he called me. We spoke for about half an hour. He called me from London. He denied he was a traitor... (he told me) he wrote to Vladimir Putin asking to be fully pardoned and to be allowed to visit Russia. His mother, brother and other relatives were (in Russia)."
Russia's ambassador to the UK sent his well wishes to Mr Skripal and his daughter on Friday, saying he hoped for their recovery.
Alexander Yakovenko also wrote to Wiltshire Police detective sergeant Nick Bailey, who was left seriously ill after he was exposed to the poison as he went to the Skripal's aid.
Mr Bailey said his experience had been "completely surreal" after he was discharged from hospital.