Hitting out at the Government, Russia’s UK embassy tweeted a picture from zombie film 28 Days Later, complete with its biohazard logo.
Its message said: “28 days passed since the poisoning of Sergei & Yulia Skripal. UK hasn’t complied with its obligation under the consular convention to provide access to the Russian citizens and the course of investigation.”
Former double agent Sergei Skripal and his daughter Yulia are still in hospital after being poisoned by deadly nerve agent novichok on 4 March.
Russia has said it “insists” on seeing Ms Skripal after her condition dramatically improved. She is now understood to conscious and talking.
The UK government – which claims the Russian state is behind the attempted murders – is looking into the legality of the request, and also considering “the rights and wishes” of the 33-year-old.
Her father remains seriously ill and unresponsive.
Another tweet by the embassy showed a picture of a golden key with the words: “Do unto others as you would have them do unto you”.
It added: “Reputation matters. After declining Russia access to Russian nationals in UK, why should @foreignoffice expect other countries to satisfy similar British requests?”
As tit-for-tat expulsions continue, the first Russian diplomats to be kicked out of the US arrived back in Moscow on Sunday.
America has expelled 60 Russians, joining many European countries who also asked diplomats to leave in solidarity with the UK.
Defence Secretary Gavin Williamson said the Kremlin had unleashed a “tidal wave of smears, lies and mockery” since the poisonings.
Writing in the Sunday Telegraph, he called the attack “illegal and contemptuous” and said President Putin was using “hybrid capabilities to subvert, undermine, and influence countries around the world”.
Russia continues to strongly deny any involvement and has responded to the West by throwing out an equal number of diplomats.
It has also published 14 questions about the investigation into the poisonings.
They include asking “what specific antidotes” the Skripals had been given and if novichok had ever been “researched, developed or produced in the UK”.
International chemical weapons experts are studying samples from Salisbury to see if they agree with the UK view that Russia was to blame.
Russia also tweeted on Sunday about murdered businessman Nikolai Glushkov, who was found dead in his London home last month.
The embassy’s tweet, which featured the 20mph speed limit sign, again protested over a lack of access to the case.
It said: “20 days passed since the murder of Nikolay Glushkov in London. UK hasn’t complied with its obligation under the consular convention to provide access to the course of investigation.”
A post-mortem examination said the 68-year-old had died from “compression to the neck”.
Counter-terror officers are leading the investigation but have said there is nothing to suggest a link with the Salisbury case.
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Mr Glushkov, a retired financial director for Russian airline Aeroflot, was wanted over fraud allegations in his homeland.
He was also a close friend of Vladimir Putin critic Boris Berezovsky, who died in 2013.