Mr Skripal, who remains in a coma along with his daughter Yulia, has been living in the United Kingdom since 2010 after being convicted of selling secrets to British intelligence.
According to Timoshkov, Skripal did not see himself as a "traitor".
Porton Down chief executive Gary Aitkenhead told the BBC: "We have got the highest levels of controls, of security around the work that we do here".
Alexander Yakovenko 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 Skripals' aid.
He also asked to be allowed to return to Russian Federation because he wanted to see his mother, brother and other relatives.
Gary Aitkenhead said suggestions by Russian Federation that the proximity of the labs to the incident in Salisbury might be somehow suspicious were "frustrating".More news: 'Jayalalithaa refused to go to hospital', claims Sasikala
More news: Lockdown lifted after 4th bomb threat at Hernando County school
More news: Europe gets last minute reprieve from Trump tariffs
It said anyone in either venue between 13:30 GMT on Sunday 4 March and closure on Monday should arrange to have their clothes collected and they will be compensated.
On Friday, EU leaders promised an "unprecedented" diplomatic response to the attack after backing UK Prime Minister Theresa May's assertion that Moscow was responsible.
The bloc is recalling its ambassador to Russian Federation for "consultations" on the Salisbury attack.
Cichocki, who is responsible for Eastern affairs and security policy, added that Poland wants a "clear position" in the European Union and North Atlantic Treaty Organisation which would express solidarity with Britain while pointing to "Russia's responsibility and duty" to respond to British allegations "instead of arrogantly and cynically repudiating them".
The father and daughter were rendered unconscious after being attacked with a nerve agent in Salisbury.
He said: "Many people shunned him".
Alexander Vakovenko wrote: "I would like to express my honest gratitude to you for your bravery when reacting to the assault on two Russian nationals, Sergei and Yulia Skripal, on 4 March in Salisbury, who I hope will get well soon too".