Ex-spy Sergei Skripal on the mend and is "improving rapidly," says Salisbury Hospital

She broke her public silence on Thursday, saying how the nerve agent poisoning on March 4 had been a disorientating experience but explained how her “strength is growing daily”.

Her comments came shortly after Russian TV reported that she had contacted a relative in Moscow to say she and her father were recovering and that she would soon be discharged.

It was only a few days ago that both remained in hospital intensive care with some reports suggesting they would never recover from being poisoned by the Novichok nerve agent.

Now, however, the prospect of their release from hospital appears to be growing although it is still not known how the authorities will handle their departure securely given the brazen attempt on their lives using a military grade nerve agent. Their would-be assassin is still at large.

In Salisbury, Dr Christine Blanshard, medical director at the local hospital, gave an update on the Skripals, saying how Yulia’s condition had improved so much that she could “look forward to the day when she is well enough to leave the hospital”.

She added: "Any speculation on when that date will be is just that; speculation. In the meantime, Yulia has asked for privacy while she continues to get better; something I'd like to urge the media to respect.”

Dr Blanshard went on: “I also want to update you on the condition of her father, Sergei Skripal. He is responding well to treatment, improving rapidly and is no longer in a critical condition. As you'll appreciate, I won't be giving any further updates at this time."

The Russian Embassy in London reacted swiftly, tweeting: “Good news!"

Moscow has appealed for the UK to issue visas for relatives to visit the Skripals in hospital.

Viktoria Skripal, Yulia’s cousin, said she was “pretty sure” the UK authorities were intent on denying her a visa to visit Britain to see her relatives.

In contrast, she told Sky News how the Russian authorities had been "very helpful" and wanted her to see her relatives.

Earlier, Russia warned Britain that it was "playing with fire and will be sorry" over the poisonings as the two countries traded jibes at the United Nations.

On Wednesday, Russia lost a vote at the Organisation for the Prohibition of Chemical Weapons in The Hague on its demand for its experts to be involved in testing samples of the substance used in the Salisbury attack. The OPCW is due to report its conclusions next week on the nerve agent.

Meanwhile, it was revealed two guinea pigs were found dead at Mr Skripal's home after the property was sealed off for investigations.

The Department for Environment, Food and Rural Affairs added a cat was also found in a distressed state at the house and a decision was taken to euthanise it.

The Russian Embassy seized on the development, saying: "It is difficult to avoid the impression animals have been disposed of as an inconvenient piece of evidence."

Elsewhere, a row broke out after Labour’s Chris Williamson, a close ally of Jeremy Corbyn, defied his party leadership’s advice and went on The Kremlin-backed RT channel to argue the Salisbury attack was being used to distract attention from Brexit; a line adopted by Moscow.

The former Shadow Minister said: “It seems to me the Government were indulging in political point-scoring, particularly Boris Johnson, who raced ahead of the evidence and used this terrible incident not so much as a smoking gun but as a smoke-screen.

“It was very convenient for the Government to use it as a way of diverting attention away from Brexit and economic policy,” added the Derby MP.

Senior Tory MP Nigel Evans said it was “depressing” that a close ally of the Labour leader was “prepared to mouth similar messages to Kremlin propaganda on state-owned Russia Today”.

Tim Farron, the former Liberal Democrat leader, added: “It is utterly shameful that MPs are doing Putin's dirty work for him.”