Russia's Foreign Ministry on Sunday rejected a British claim that the Kremlin is seeking to replace Ukraine's government with a pro-Moscow administration, and that former Ukrainian lawmaker Yevheniy Murayev is a potential candidate.
Britain's Foreign Office on Saturday also named several other Ukrainian politicians it said had links with Russian intelligence services, along with Murayev who is the leader of a small party that has no seats in Parliament.
Those politicians include Mykola Azarov, a former prime minister under Viktor Yanukovych, the Ukrainian president ousted in a 2014 uprising, and Yanukovych's former chief of staff, Andriy Kluyev.
"Some of these have contact with Russian intelligence officers currently involved in the planning for an attack on Ukraine," the Foreign Office said.
Murayev told The Associated Press via Skype that the British claim "looks ridiculous and funny" and that he has been denied entry to Russia since 2018 on the grounds of being a threat to Russian security. He said that sanction was imposed in the wake of a conflict with Viktor Medvedchuk, Ukraine's most prominent pro-Russia politician and a friend of Russian President Vladimir Putin.
Murayev's Nashi party — whose name echoes the former Russian youth movement that supported Putin — is regarded as sympathetic to Russia, but Murayev on Sunday pushed back on characterising it as pro-Russia.
"The time of pro-Western and pro-Russian politicians in Ukraine is gone forever," he said in a Facebook post.
"Everything that does not support the pro-Western path of development of Ukraine is automatically pro-Russian," Murayev told The AP.
He also said he supports Ukraine having neutral status and believes that "striving for NATO is tantamount to continuing the war". Ukrainian forces and Russia-backed separatists have been fighting in the country's east since 2014, a conflict that has killed more than 14,000.
Ukrainian political analyst Volodymyr Fesenko described Murayev as a significant figure in Ukraine's pro-Russia camp, but added: "Murayev is a second-place player. I don't think Murayev has direct connections in the Kremlin."
The UK government made the claim based on an intelligence assessment, without providing evidence to back it up. It comes amid high tensions between Moscow and the West over Russia's designs on Ukraine and each side's increasing accusations that the other is planning provocations.
"The disinformation spread by the British Foreign Office is more evidence that it is the NATO countries, led by the Anglo-Saxons, who are escalating tensions around Ukraine," Russian Foreign Ministry spokeswoman Maria Zakharova said on the Telegram messaging app Sunday. "We call on the British Foreign Office to stop provocative activities, stop spreading nonsense."
British Foreign Secretary Liz Truss said the information "shines a light on the extent of Russian activity designed to subvert Ukraine, and is an insight into Kremlin thinking".
Truss urged Russia to "deescalate, end its campaigns of aggression and disinformation, and pursue a path of diplomacy," and reiterated Britain's view that "any Russian military incursion into Ukraine would be a massive strategic mistake with severe costs".
Britain has sent anti-tank weapons to Ukraine as part of efforts to bolster the country's defences against a potential Russian attack.
Mark Galeotti, who has written extensively on Russian security services, said: "I can't help but be skeptical" about the British claim.
"This is one of those situations where it is hard to know whether what we're facing is a genuine threat, a misunderstanding of the inevitable overtures that were being made to various Ukrainian figures by Russians or 'strategic communication' — which is what we call propaganda these days when we're doing it," Galeotti, who is honorary professor of Slavonic and East European Studies at University College, London, told the AP.
US Secretary of State Antony Blinken said he could not comment specifically about the British claim, but "we've been warning about just this kind of tactic for weeks".
"This is very much part of the Russian tool kit," he said in an interview on CNN. "It runs the gamut from a large, conventional incursion or invasion of Ukraine to these kinds of destabilising activities in an attempt to topple the government. And it's important that people be on notice about that."
The UK government's unusual decision to release the thinking of British spies, though not the evidence behind it, comes as Prime Minister Boris Johnson is distracted by a leadership crisis over lockdown-breaching parties by his staff during the coronavirus pandemic.
Keir Giles, a Russia expert at the international affairs think-tank Chatham House, said the British warning was a sign of "the UK effectively taking the lead of a strong NATO and European response to Russia's threats to Ukraine.
"With the US apparently willing to engage with Russia's demands on Moscow's terms, and the EU irrelevant and asleep at the wheel, it has fallen to the UK to deal with the challenge both in terms of rhetoric … and in terms of direct action, raising the likely cost of a Russian incursion in Ukraine by providing direct shipments of defensive munitions," Giles said.
Amid diplomatic efforts to defuse the crisis, UK Defense Secretary Ben Wallace is expected to meet Russian Defense Minister Sergei Shoigu for talks in Moscow. No timing has been given for the meeting, which would be the first UK-Russia bilateral defence talks since 2013.
The US has mounted an aggressive campaign in recent months to unify its European allies against a new Russian invasion of Ukraine. The White House called the UK government assessment "deeply concerning" and said it stands with the duly elected Ukrainian government.
"The Ukrainian people have the sovereign right to determine their own future, and we stand with our democratically elected partners in Ukraine," National Security Council spokeswoman Emily Horne said.
The assessment came as President Joe Biden spent Saturday at the presidential retreat Camp David outside of Washington huddling with his senior national security team about the Ukraine situation. A White House official said the discussions included efforts to de-escalate the situation with diplomacy and deterrence measures being coordinated closely with allies and partners, including security assistance to Ukraine.
Lawless reported from London. AP writers Anna Frants in Moscow and Matthew Lee and Zeke Miller in Washington contributed to this report.