Western officials have warned of their “serious concern” that Vladimir Putin could order chemical weapons to be used on Ukraine’s capital.
In an assessment, they say an “utterly horrific” attack on Kyiv could be unleashed as Russian forces attempt to overcome the logistical issues that have apparently plagued the convoy heading for the city.
In a briefing to journalists, one official said: “I think we’ve got good reason to be concerned about possible use of non-conventional weapons, partly because of what we’ve seen has happened in other theatres.
“As I’ve mentioned before, for example, what we’ve seen in Syria, partly because we’ve seen a bit of setting the scene for that in the false flag claims that are coming out, and other indications as well.
“So it’s a serious concern for us.”
The officials also said there is hope that China will push for an end to the violence but that there is disappointment that Beijing has so far not been clearer on the “unwarranted invasion” being unacceptable.
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It comes after Downing Street said the Prime Minister, who met with his Polish counterpart in London Mateusz Morawiecki yesterday, believed it “wouldn’t be tenable for NATO pilots and NATO-badged jets to be shooting down Russian aircraft”.
Allies fear that such a move would risk provoking a wider conflict, and the Western official said the difference between the weapons is that the existing support is “defensive”.
The official also warned that Russian troops on the ground are “continuing to tighten the noose” around Kyiv.
They said: “This is definitely not over, they are still set on moving in, we’re reasonably confident. It’ll be utterly horrific when they do, I’m sure.”
A second official warned of more repression of the people in Russia to come as the Russian president faces an extended campaign that he did not prepare his citizens or troops for.
They said: “This will end because of a combination of factors, one of them is the impact of sanctions, but it’s only one of them.
“I think unfortunately the state’s response will not be to think about the best interests of ordinary Russians the state’s response will be to double down, to control information, to blame other people and try and see what they can do by the partnership they can do with China and a few other countries to offset the worst of it.”
On Tuesday, UK ambassador to the Netherlands Joanna Roper posted a statement on the website of the Organization for the Prohibition of Chemical Weapons, urging the organisation to be vigilant.
She said: “The UK remains concerned that Russia may use the pretext of chemical weapons to try to justify its illegal actions in Ukraine and we know only too well that Russia is also prepared to use chemical weapons against others.”
It came after the UK delegation to the global chemical weapons watchdog and a group of supporters walked out of a meeting in The Hague in response to what the delegation called “unacceptable Russian falsehoods on Ukraine”.
On Wednesday, Russia said it had uncovered a military biological weapons programme in Ukraine – a claim described by the US as “absurd propaganda”.
During the civil war in Syria, despite evidence that chemical weapons had been used on civilians by the Bashar al Assad regime, Russia – which was supporting Syrian forces militarily – used its UN Security Council veto to prevent action being taken against its ally.