Paula Stevenson, Hayley Fullerton's mother, said she was "shocked" by the Coroner's verdict that there were "serious failures" but not "gross" failures by Birmingham Children's Hospital.
More top news
Mr Corbyn gave a forthright "no" when asked by ITV News Political Correspondent Chris Ship on Friday.
What is VX and what makes it so dangerous? ITV News asks an expert.
Unemployed plasterer Trevor Timon had been cleared of Oliver Dearlove's murder but admitted manslaughter.