TEHRAN, Young Journalists Club (YJC) - At a special meeting to discuss the case at the Organization for the Prohibition of Chemical Weapons in The Hague, the Netherlands, the British envoy said that a joint investigation, as proposed by Russia, would force "a victim to engage the likely perpetrator."
Acting U.K. Permanent Representative John Foggo said that "to do so would be perverse," adding that Moscow's demand showed "disdain."
Britain, backed by its European and U.S. partners, has blamed Russia for the March 4 nerve agent attack on Sergei Skripal and his daughter Yulia in the city of Salisbury, an accusation that Russia vehemently denies.
Wednesday's meeting at the international chemical weapons control body was called at the request of Moscow, which has pushed for Britain to provide evidence backing its claim that Russia was responsible.
"We are ready for a comprehensive, highly professional and open cooperation on the Skripal case with the U.K. both in a bilateral format and within the OPCW," Russia's foreign affairs spokeswoman Maria Zakharova said.
On Tuesday, the chief of Britain's defense laboratory said its scientists haven't tracked down the "precise source" of the nerve agent used in the attack. Britain had earlier identified the agent as a Soviet-developed type known as Novichok.
The case has plunged relations between the West and Russia to their lowest ebb since the Cold War, with multiple tit-for-tat diplomatic expulsions in numerous countries.
In Moscow, Russia's spymaster claimed the poisoning was staged by U.K. and U.S. intelligence agencies.
Sergei Naryshkin, director of Russia's Foreign Intelligence Service, the top KGB successor agency, said the poisoning was a "grotesque provocation rudely staged by the British and U.S. intelligence agencies."
Speaking Wednesday at an international security conference organized by the Russian Defense Ministry, Naryshkin said the poisoning was the latest U.S. effort to undermine Russia and was akin to its practices during the Cold War.
Meanwhile the 28-nation EU, of which Britain is still a member, lamented Moscow's refusal to give information to Britain.
"Instead, we witnessed a flood of insinuations" targeting several EU member states, envoy Krassimir Kostov of Bulgaria, which currently holds the EU presidency, told the council meeting.
In a separate speech on the use of chemical weapons Wednesday, a British diplomatic official condemned Russia for flouting international rules and hurting the chemical weapons watchdog.
"Russia repeatedly sought to undermine the OPCW - the very organization set up to put an end to the barbarity of chemical weapons attacks," Alistair Burt, minister of state for the Middle East, said.