Britain's UN ambassador has emphatically denied a Russian military claim that the United Kingdom staged an alleged chemical attack in Syria, calling it "bizarre" and "a blatant lie."
The Russian military has blamed the UK for the attack that reportedly killed 75 civilians, saying that the alleged chemical attack in Douma was staged and directed by Britain.
The spat came as the UN Secretary-General Antonio Guterres warned that the Cold War is back "with a vengeance" with allied strikes potentially imminent.
Earlier Labour leader Jeremy Corbyn accused the government of "waiting for instructions" from US president Donald Trump on what to do over Syria.
How has Russia claimed Britain was involved in the Syria attack?
Russia has released statements from medics at Douma's hospital, who said a group of people with video cameras entered the hospital, shouting that patients had been struck with chemical weapons.
Russian Defence Ministry spokesman, Major General Igor Konashenkov, said Britain was "directly involved in the provocation".
He claimed "powerful pressure from London was exerted on representatives of the so-called White Helmets to quickly stage the premeditated provocation."
What did the British ambassador say to rubbish the claims?
British Ambassador Karen Pierce responded, saying she wanted, "to state categorically ... that Britain has no involvement and would never have any involvement in the use of a chemical weapon."
She added: "This is grotesque ... it's some of the worst piece of fake news we've yet seen from the Russia propaganda machine."
She spoke after an emergency meeting of the UN Security Council called by Russia to address US threatened military action in response to last weekend's attack in the Damascus suburb of Douma.
UN Secretary-General Antonio Guterres told the same meeting: "The Cold War is back - with a vengeance but with a difference."
He said the Middle East is in such "chaos" that it has become a danger to international peace and security - and Syria "represents the most serious threat".
The UN chief said the highly volatile situation in the region risks "escalation, fragmentation and division as far as the eye can see, with profound regional and global ramifications".
How does Corbyn want Britain to respond to the attack?
Labour is calling for the government to put any decision on military action to a vote in the commons.
Mr Corbyn on Friday called for an independent UN-led inquiry into the devastating air strike in Douma last Saturday that killed a reported 75 civilians and injured 500 more, presumed to have been carried out by the Bashar al-Assad regime.
"Further UK military intervention in Syria's appalling multi-sided war risks escalating an already devastating conflict," Corbyn said, adding that "ministers should take their proposals, such as they are, to parliament".
"The government appears to be waiting for instructions from President Donald Trump on how to proceed. But the US administration is giving alarmingly contradictory signals," he said.
How close are British force to military action?
After a two-hour emergency meeting on Thursday, Cabinet ministers "agreed on the need to take action" however it was not made clear what the response would be.
Reporting from the British base ITV News Correspondent Juliet Bremner said that the risk of Russian missiles made it "very unlikely" piloted aircraft would be flown over Syrian airspace.
She said: "I understand that an additional sentinel spy plane was flown into this base overnight that will be used to recce sites in Syria."
Downing Street said the UK will continue to work with the US and France to coordinate an international response.
How has Russia responded to imminent action from the West?
Russian Foreign Minister Sergei Lavrov said on Friday he hoped history would not repeat itself.
"God forbid anything adventurous will be done in Syria following the Libyan and Iraqi experience."
He added that even the smallest miscalculation in Syria could be disastrous.
The Russian Embassy in the UK also weighed in on the debate, saying it was "concerned about the decision of the Cabinet to "take action" amid the reports on the possible UK participation in the military operation against Syria".
At the request of the Syrian Government the OPCW sent a fact-finding team to Douma to investigate whether chemical weapons were used.
"Military strikes may be used to cover up all the evidence, or lack thereof, on the ground. Such a decision, if it's taken, in violation of the international law and the Charter of the United Nations may well mark the latest in the series of the reckless military adventures by the UK," the embassy added.
Referencing the Chilcot inquiry, the Russian ambassador hinted that the UK Government were "deliberately" misleading the public.
"The infamous aggression against Iraq in 2003 immediately comes to mind, when the then-Prime Minister Tony Blair deliberately misinformed the Parliament and the public.
"It is well known how it ended - with Chilcot inquiry delivering a condemnatory verdict. It's essential to avoid any steps which could escalate the tensions."