Russian ex-spy Sergei Skripal has been discharged from hospital after being exposed to a nerve agent.
The 66-year-old had been staying at Salisbury District Hospital after the attack on March 4, along with his daughter Yulia, 33, and Det Sgt Nick Bailey.
The news was announced in a statement from the hospital.
Director of Nursing Lorna Wilkinson said the incident had posed an "huge and unprecedented challenge".
Yulia and Det Sgt Bailey had already been discharged.
The hospital said they had all been "acutely unwell", and had needed intense treatment to keep them alive until their bodies could produce more enzymes to replace those that had been poisoned.
Russian ambassador to the UK Alexander Yakovenko welcomed the news that Sergei Skripal has been discharged from hospital.
He reiterated the demand for consular access to the ex-spy and his daughter Yulia.
Speaking at a press conference at his official residence in London he said:
"We are happy that he is all right.
"We are still demanding access to these people. We want to understand how they feel.
"We want them to tell (us) personally what they want. If they don't want our assistance, that's fine, but we want to see them physically."
Mr Yakovenko claimed that the UK is violating international law by not granting access to the Skripals, and stepped up demands to be allowed to see them.
He also suggested the pair may be being detained by the British state, calling the father and daughter "isolated".
"You can call it kidnap," he added.
Salisbury District Hospital chief executive, Cara Charles-Barks, welcomed the "fantastic" news and praised the work of health staff.
"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."
It comes just days after the head of MI5, Andrew Parker, said the nerve agent attack had been a “deliberate and targeted” act, placing the blame with Russia.
In his first public comments since the poisoning, Mr Parker accused the Kremlin of “flagrant breaches of international rules” and warned that the Russian government was pursuing an agenda through “aggressive and pernicious actions” by its military and intelligence services.