The British Foreign Office has described a Russian request for a meeting with Foreign Secretary Boris Johnson as a "diversionary tactic".

The Russian embassy in London had requested a meeting between its envoy and Mr Johnson to discuss the investigation of the poisoning of an ex-Russian spy and his daughter in Salisbury.

The Foreign Office confirmed it had received the request for a meeting between Ambassador Alexander Yakovenko and Boris Johnson and would respond in due course.

A spokesperson for the Foreign Office said Russia's response to the investigation had been unsatisfactory so far, that it had failed in their attempts in the United Nations and with the international chemical weapons watchdog earlier this week and that they now seemed to be pursuing a different diversionary tactic.

Yesterday, the hospital in Salisbury said Sergei Skripal was no longer in a critical condition. 

In a statement, the hospital said he responded well to treatment. 

Meanwhile, Russia yesterday requested an explanations over Britain's refusal to issue a visa to the niece of Mr Skripal, according to reports from the RIA news agency.

The UK Home Office confirmed yesterday that Viktoria Skripal, who had planned to travel to Britain to take Mr Skripal's daughter, Yulia, back to Russia, had been denied a British visa.