Russian spies allegedly hacked into the personal phone of former Prime Minister Liz Truss, uncovering a raft of top-secret information and unleashing “pandemonium”, according to reports.
The Kremlin hackers gained access to negotiations with international allies about arms shipments to Ukraine, as well as Ms Truss’ personal messages to key ally Kwasi Kwarteng, the Mail on Sunday reported.
The breach reportedly took place this summer, during then-Foreign Secretary Ms Truss’ successful bid to replace Mr Johnson as Conservative leader and Prime Minister.
Those messages allegedly included criticisms of Boris Johnson made by both Ms Truss and Mr Kwarteng, which could lead to a risk of possible blackmail.
On learning of the breach, Mr Johnson and civil service boss Simon Case kept it secret. The Cabinet Office declined to comment on the claims.
The phone was reportedly so compromised that officials locked it away in a safe.
A source told the Mail: “This caused absolute pandemonium.
“It is not a great look for the intelligence services if the Foreign Secretary’s phone can be so easily plundered for embarrassing personal messages by agents presumed to be working for Putin’s Russia.”
Labour’s shadow home secretary Yvette Cooper said: “There are immensely important national security issues raised by an attack like this by a hostile state which will have been taken extremely seriously by our intelligence and security agencies. “There are also serious security questions around why and how this information has been leaked or released right now which must also be urgently investigated.
“It is essential that all of these security issues are investigated and addressed at the very highest level and we need to know that the Government recognises the gravity of this and the importance of fully protecting our national security.”
Liberal Democrat foreign affairs spokesperson Layla Moran said: “We need an urgent independent investigation to uncover the truth. Was Liz Truss’s phone hacked by Russia, was there a news blackout and if so why?
“If it turns out this information was withheld from the public to protect Liz Truss’s leadership bid, that would be unforgivable.”
A UK government spokesperson said: “We do not comment on individuals’ security arrangements.
“The Government has robust systems in place to protect against cyber threats. That includes regular security briefings for Ministers, and advice on protecting their personal data and mitigating cyber threats.”
The news comes after Russian president Vladimir Putin branded Ms Truss “crazy” this week for bringing up Russian use of nuclear weapons.
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Mr Putin also claimed the era of Western dominance was over in a fresh rambling speech on Thursday.
In the same week he rehearsed eradicating Britain and the US in a series of nuclear drills, according to a top Russian military expert, he again insisted the “dominion of the world” by the West would no longer be tolerated.
“Dominion of the world is what West has decided to stake in this game. It is a dangerous, deadly and dirty game.”
“The West is no longer able to dictate its will to the humankind but still tries to do it, and the majority of nations no longer want to tolerate it,” the Russian autocrat said at a speech to a think tank.
Ms Truss was replaced by Rishi Sunak as Prime Minister this week after less than two months, following a disastrous spell leading the country that plunged financial markets into turmoil.