Skripal’s release follows that of his daughter, Yulia, and DS Nick Bailey, who were also in March.

The hospital said: “While these patients have now been discharged, their right to patient confidentiality remains and limits us from giving detailed accounts of the treatment these individuals received.

“However, treating people who are so acutely unwell, having been poisoned by nerve agents, requires stabilising them, keeping them alive until their bodies could produce more enzymes to replace those that had been poisoned.”

The Salisbury district hospital chief executive, Cara Charles-Barks, said it was fantastic news that Skripal was well enough to be discharged.

“That he, Yulia and DS Bailey have been able to leave us so soon after coming into contact with this nerve agent is thanks to the hard work, skill and professionalism of our clinicians, who provide outstanding care to all our patients, day in and day out,” she said.

“This has been a difficult time for those caught up in this incident – the patients, our staff and the people of Salisbury. I want to thank the public for their support, and I want to pay a special tribute to both the clinical staff here at the trust and those who work so hard behind the scenes. They’ve demonstrated the very best of the NHS.”

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