More heartbreaking scenes of torture and murder of Ukrainian civilians will come to light in the coming months as Russia tries to impose sham referendums on parts of regions it controls, intelligence chiefs fear.
Western sources today said that credible evidence is being uncovered by governments and NGOs of horrendous treatment meted out by Valdimir Putin 's forces, six months after the invasion started.
Sources are understood to be "particularly concerned" about filtration camps amid chilling reports of torture and murder, with a report by Human Rights Watch highlighting sickening treatment of people in Donetsk.
Russian occupiers are desperate to impose referendums on the population in an effort to convince the world that Ukrainians want to be assimilated into a larger Russia - but results should be viewed as having no credibility at all, sources said.
Meanwhile, there is optimism that Ukraine is making progress in reclaiming territory around the port city of Kherson, with many Russian units lacking combat effectiveness due to depleted numbers.
Putin, whose movements are limited due to fears around his security, has embarked on propaganda visits to try and tackle waning enthusiasm for his war in recent days, sources say.
It comes as the British national security advisor, Sir Stephen Lovegrove, vowed that UK support for Ukraine would not waver.
He said in a statement released today: "It’s been more than six months since Putin launched his unprovoked, illegal war bringing untold suffering to the innocent people of Ukraine and there is increasing evidence of atrocities committed by Russian forces. Putin's invasion has hurt people across the globe, causing price rises and food insecurity, including for many who were already vulnerable, as well as the desperate bloodshed.
"Ukraine’s resistance has inspired the world and shown huge courage in the face of brutality. Now that courageous resistance has stalled the Russian advance and demonstrated the determination of the Ukrainian people and Armed Forces to retake their sovereign territory.
"The risks around this terrible conflict continue as Putin finds he can’t make progress, his forces suffer heavy losses, and sanctions continue to degrade his war machine and take money out of the pockets of Russia's richest people. At the same time Russia is trying and failing to impose a veneer of legitimacy on the areas it temporarily controls, including through plans for staged sham referenda. It will not succeed.
"The UK and our allies will continue to provide humanitarian, economic and military assistance. Our support for Ukraine and its people will not waver."
