Yulia Skripal has admitted she is “lucky to have survived” the nerve agent attack on her and her father and spoken of her determination “in the longer term” to return to Russia.

In her first televised appearance, Miss Skripal, 33, said the attempted assassination had taken a “devastating” toll and described the clinical treatment to keep her alive as “invasive, painful and depressing”.

Miss Skripal read out loud and in Russian a prepared statement in which she described her recovery as “slow and painful”. A scar on her throat, presumably caused by a tracheotomy to help her breathe following the attack, is clearly visible in the video footage released on Wednesday evening.

The message is an important signal to the Russian people that Miss Skripal remains in the UK, under the protection of the British authorities and of her own free will.

The Kremlin, which denies any involvement, has accused the British government of holding her captive and has repeatedly demanded access to her. As recently as the weekend, Vladimir Putin insisted that if Russian-manufactured, military-grade Novichok nerve agent had been used in the attack, then Miss Skripal and her 66-year-old father Sergei would have been killed.