Maria Zakharova, the Russian foreign ministry spokeswoman, described the British allegations as "insane" and accused the country of "Russophobia" as well as hiding "the truth" about the Skripal case.
Speaking at a routine press conference, Zakharova told reporters she wanted to comment on "the statements made by the prime minister of Britain [Theresa May] in parliament with completely insane accusations towards the Russian Federation, our entire country, our entire people".
"In connection with the introduction by Britain of unfriendly steps towards Russia, we plan to introduce reciprocal steps, without doubt... They are currently being worked on and will be adopted in the near future," she said.
She accused Britain of refusing to cooperate with Moscow on the investigation into the incident.
"We are extremely concerned by what happened a few days ago on British territory, we view with great concern all information we are receiving about the use of chemical weapons on British territory," Zakharova told the briefing.
"Britain is refusing to provide any factual information on this case. There is no mention about, for example, providing Russia with samples of the substance that was found at the crime scene," she said.
"I can confirm again, Britain has not provided to Russia any information, any details that might shed some light on the situation."
New evidence has left Theresa May’s Russian spy story in tatters -->