Former foreign secretary Sir Malcolm Rifkind has told talkRADIO that it's too early to say Sergei Skripal was poisoned on the orders of the Kremlin, and it would be "very odd" for Vladimir Putin to attempt something like this.
Rifkind, who held the foreign office brief under Sir John Major, told Julia Hartley-Brewer that "the best judgement has to be at this moment that there is a Russian connection."
However he added that "there are a lot of rogue elements" in Putin's government, and Skripal could have been killed by Russian criminals living in London.
Rifkind says the incident is "hugely embarrassing" for Russia, and will only encourage the West to enforce sanctions against the country - something Putin has railed against in the past.
But Julia countered by suggesting this is about "sending out a message" to Russian agents and the British government.
If the Russian government's involvement is proven, Rifkind said, Britain would have to examine "whether we can have normal diplomatic relations" with Putin and his government.