Sergei Skripal’s niece has been refused a visa to visit Britain for a second time as he continues to be treated for nerve agent exposure.

A Home Office spokesperson said: “We have refused a visa application from Viktoria Skripal on the grounds that she did not meet the requirements of the immigration rules.”

Viktoria Skripal previously attempted to gain a visa to travel from Moscow in early April and was turned down on the same basis, with her cousin Yulia publicly saying she did not wish to see her.

Ms Skripal has appealed to the government to let her visit her uncle and cousin, who are recovering following the attack in Salisbury on 4 March.

In April she revealed what was claimed to be recorded comments from phone conversations, but in a statement released last month Yulia said that “no one speaks for me, or for my father, but ourselves”.

“I thank my cousin Viktoria for her concern for us, but ask that she does not visit me or try to contact me for the time being,” she added.

“I have access to friends and family, and I have been made aware of my specific contacts at the Russian embassy who have kindly offered me their assistance in any way they can.

“At the moment I do not wish to avail myself of their services, but, if I change my mind I know how to contact them.”

Mr Skripal remains at Salisbury District Hospital, where officials said his condition is improving and he is no longer in a critical condition.

His daughter was discharged last month and is recovering in an undisclosed location.

Russian officials have repeatedly attempted to cast Yulia’s situation as “forced isolation” and cast doubt on whether statements “really belong to Yulia”.

The Kremlin has repeatedly denied any role in the nerve agent attack on Mr Skripal, a former double agent who was jailed for treason in Russia before moving to the UK following a 2010 spy swap.

Police concluded that nerve agent had been smeared on the door handle of his home in a quiet Salisbury cul-de-sac, affecting both him and his daughter during her visit from Russia.

Members of the emergency services, including DS Nick Bailey, were also affected by the substance and decontamination work continues across the Wiltshire city to rid sites they visited of any traces.

Skripal attack aftermath – in pictures Show all 15 1 /15 Skripal attack aftermath – in pictures Skripal attack aftermath – in pictures Scene of attack Members of the emergency services in hazard suits fix the tent over the bench where Sergei and Yulia Skripal were found unconscious on a park bench in Salisbury in March 2018. Getty Skripal attack aftermath – in pictures Victim - Sergei Skripal The retired Russian colonel and former double agent for MI6 was in a critical condition in hospital for more than two months after being exposed to novichok in Salisbury. He was given refuge in the UK after being jailed in Moscow for treason. Mr Skripal came to Britain as part of a high-profile “spy swap” in 2010 in which four men were exchanged for ten Russian "sleeper agents" in the US. In this image he is speaking to his lawyer from behind bars in Moscow in 2006. AP Skripal attack aftermath – in pictures Victim - Yulia Skripal Yulia Skripal was struck down by a novichok poison alongside her father Sergei. Facebook Skripal attack aftermath – in pictures Scene of attack A police officer stands guard outside a branch of the Italian chain restaurant Zizzi where the pair dined at before falling ill. It was boarded off whilst investigators worked on the building and later found traces of the chemical weapon within it. AFP/Getty Skripal attack aftermath – in pictures Scene of attack Large areas of central Salisbury were cordoned off by police following the discovery of the Skripals. Traces of nerve agent were also found in The Mill pub. PA Skripal attack aftermath – in pictures Victim - Nick Bailey Detective Sergeant Nick Bailey, rushed to the aid of the Russian ex-spy and his daughter who were targeted with a nerve agent. He was hospitalized after aiding them and didn't leave until three weeks after the attack. Wiltshire Police/Rex Skripal attack aftermath – in pictures Police investigation - Skripal’s home Police believe they were poisoned at home, and detectives found the highest concentration of novichok on the front door of Mr Skripal’s house. Getty Skripal attack aftermath – in pictures Theresa May visits scene of attack Britain's Prime Minister Theresa May spokes with Wiltshire Police's Chief Constable Kier Pritchard near where the Skripal's were found. Britain expelled 23 Russian diplomats over the nerve agent poisoning and suspended high-level contacts, including for the World Cup on March 14. Theresa May told parliament that Russia had failed to respond to her demand for an explanation on how a Soviet-designed chemical, Novichok, was used in Salisbury. AFP/Getty Skripal attack aftermath – in pictures Skripal days before attack Sergei Skripal days before he was exposed to Novichok, that has left him fighting for life. ITV News Skripal attack aftermath – in pictures Police investigation - military involvement British soldiers were deployed soon after the attack to help a counter-terrorism investigation into the nerve agent attack. One of the places they were asked to help out with was Skripal's home and it's surrounding. They were asked to remove a vehicle connected to the agent attack in Salisbury, from a residential street in Gillingham. AFP/Getty Skripal attack aftermath – in pictures Police investigation Personnel in protective coveralls and breathing equipment cover an ambulance with a tarpaulin at the Salisbury District Hospital. AFP/Getty Skripal attack aftermath – in pictures Police investigation The investigation extended to the grave of Sergei Skripal's son Alexander in London Road cemetery. Getty Skripal attack aftermath – in pictures Police investigation The Counter Terrorism Policing Network requested assistance from the military to remove a number of vehicles and objects from Salisbury. EPA Skripal attack aftermath – in pictures Home Secretary visits scene of attack Home Secretary Amber Rudd visited the scene of the nerve agent attack at the Maltings shopping centre on 9 March. Getty Skripal attack aftermath – in pictures Yulia Skripal speaks for the first time Yulia Skripal, speaking for the first time, said she felt lucky to have survived the nerve agent attack in Salisbury which left her fighting for life. Ms Skripal said her life had been “turned upside down” by the assassination attempt. But the Russian national added she hoped to return to her homeland one day, despite the Kremlin being blamed for the attack. Reuters

The British government has accused Russia of culpability after identifying the nerve agent used as one of the Soviet-developed novichok group and the Organisation for the Prohibition of Chemical Weapons confirmed its analysis.

Investigators have not yet identified who carried out the poisoning, the national security adviser told MPs earlier this month.

Sir Mark Sedwill said police were reviewing the security of all defected Russian spies living in the UK in the wake of the unprecedented attack.

He insisted that authorities had acted “much faster” than following the murder of another former Russian spy, Alexander Litvinenko, with radioactive polonium in 2006.

Little over a week after the attack in Salisbury, Russian businessman Nikolai Glushkov was found strangled at his London home. No one has been arrested in relation to his death and police investigations continue.