Russia’s UN ambassador says UK ‘playing with fire’ by accusing Moscow of being behind last month’s nerve agent attack.

Russia has warned Britain that it is “playing with fire” by blaming Moscow for poisoning a former Russian spy and his daughter, as a war of words between the two countries escalates.

Vassily Nebenzia, Russia’s ambassador to the UN, sounded the warning on Thursday at a UN Security Council meeting in New York, called by Russia to discuss the diplomatic fallout from the poisoning of the former double agent, Sergei Skripal, and his daughter Yulia.

Diplomatic tensions between the two countries have been on the rise after what the UK and its allies alleged was a nerve-agent attack by Russia on Sergei and Yulia Skripal in the southern English city of Salisbury last month.

“I don’t even know what to say, it’s some sort of theatre of the absurd, couldn’t you come up with a better fake story?” Nebenzia told the Security Council.

“We have told our British colleagues that ‘you’re playing with fire and you’ll be sorry’.”

British statements

Earlier Karen Pierce, UK’s ambassador to the UN, told the Security Council that Britain’s actions “stand up to any scrutiny” and pledged to keep the 15-member body updated on the inquiry.

“All we’ve done has been consistent with the chemical weapons convention,” she said.

Pierce added: “We have nothing to hide … but I do fear that Russia might have something to fear.”

The UK refuses to allow Russia to join its investigation into the incident, but the British UN envoy, Pierce, said they had passed on a Russian request for consular access to Yulia Skripal and “we await her response”.

Separately, Kelley Currie, deputy US ambassador to the UN, told the Security Council: “We have stated previously and do so again today our firm belief that Russia is responsible for this chemical weapons attack on UK soil.”

Thursday’s session had been called by Russia, which is seeking to undermine Britain’s case that Moscow was responsible for last month’s attack in Salisbury.

“Novichok is not copyrighted by Russia in spite of the obviously Russian name,” said Nebenzia in his address, adding that the US and Britain had both developed the nerve agent.

Meanwhile, in a statement issued by London police on Thursday, Yulia said her health has improved rapidly, but her father remains in intensive care.

“I woke up over a week ago now and am glad to say my strength is growing daily,” she said. “I am grateful for the interest in me and for the many messages of goodwill that I have received.

“I have many people to thank for my recovery and would especially like to mention the people of Salisbury that came to my aid when my father and I were incapacitated.”