(CNN) - Key allies who share intelligence with the United States could soon be dragged into the middle of Attorney General Bill Barr's politically-charged Justice Department review of how the Russia investigation began.
President Donald Trump has said he wants Barr to look into the role key intelligence partners, including the United Kingdom and Australia, played in the origins of Russia probe. He has said he could raise the issue with the British Prime Minister Theresa May during his state visit next week and suggested he may ask her about his accusation that Britain spied on his 2016 presidential campaign.
In describing the scope of Barr's mission to declassify and study the pre-election Obama-era intelligence, among several other topics, Trump told reporters, "I hope he looks at the UK and I hope he looks at Australia and I hope he looks at Ukraine."
For now, those allies are trying to stay out of the fray, arguing it's a domestic issue. But the President has granted Barr -- not the intelligence community -- sweeping powers to decide what intelligence can be declassified.
That means Barr could potentially reveal intelligence shared with the US by other countries related to Russian election meddling and, in the process, risk damaging those critical relationships with foreign partners.
The United Kingdom and Australia are members of the critical so-called Five Eyes intelligence-sharing alliance, rounded out by the United States, New Zealand and Canada.
Both have so far publicly stayed quiet, emphasizing their friendships with the US but national security officials in those countries are watching and waiting, following closely while refraining from criticizing a process that could call into question their intelligence gathering and reveal their methods and sources.
"If the review were to declassify sensitive intelligence -- especially if doing so compromised the safety of sources -- that would cause very grave concern," a former senior British ambassador told CNN. "It could even affect the readiness of close allies like Britain to continue sharing the most sensitive material with the US."
"This is a matter for the US authorities," a senior British official in London added, while the embassy in Washington declined to comment.
One official from a Five Eyes partner said that a balance needs to be struck between the review of intelligence and national security matters with the need to protect classified information.
Australian officials declined to comment but Foreign Minister Marise Payne told a radio interviewer on Monday they don't want to "engage in a public commentary that might entirely risk that we seem to prejudice the ongoing examination of these matters in the US."
There is increased wariness because of the President's signature unpredictability but Barr is seen as a steady hand and intelligence partners are comforted by their lengthy friendships with their American counterparts.
In Britain's case, the drama surrounding Brexit also means they are keen not to rock the boat.
"For Brexit and other reasons, the British government is keen to stay closely aligned with the Trump administration, despite significant differences on climate, trade, and foreign policy," the former British ambassador said. "The UK will probably not want to say much in public about the Barr review of inter-agency links."
Trump might bring up Five Eyes spying with May
Until now, the Barr review hasn't gotten much public attention in the UK, with recent headlines dominated by the dramas surrounding Brexit, May's resignation and European Parliament elections. But the British press' attention will soon turn back to the Trump and the tension in the "special relationship" with the President's state visit to the UK next week.
Asked whether he would raise the possibility of Five Eyes countries spying on his 2016 presidential campaign, Trump told reporters on Friday he could do so with outgoing Prime Minister May.
"There's word and rumor that the FBI and others were involved, CIA were involved, with the UK, having to do with the Russian hoax," Trump told reporters on Friday. "And I may very well talk to her about that, yes."
Despite the public disagreement between Trump and the US intelligence community over whether Russia interfered in the 2016 election, the top US intelligence chief said the Barr will get "all the appropriate information" for the review of intelligence into Russia's election attacks.
But Director of National Intelligence Dan Coats warned Barr against being too public with what he declassifies.
"I am confident that the Attorney General will work with the IC in accordance with the long-established standards to protect highly-sensitive classified information that, if publicly released, would put our national security at risk," Coats said in a statement.
When asked if the Department of Justice has provided any assurances regarding the protection of intelligence provided by foreign partners, an ODNI spokesperson referred CNN to Coats' statement from last week.
The Justice Department declined to comment.
Foreign intelligence and the 2016 election
It was the Australians who tipped off the FBI that Trump campaign aide George Papadopoulos knew about the Russians having damaging emails that could influence the election, months before that information became public.
The Australians knew because Papadopoulos bragged about it to the Australian ambassador to the UK in May 2016, and they brought the tip to the FBI's attention in July 2016, after WikiLeaks started releasing hacked Democratic emails.
According to the Mueller report, which never identified Australia by name, "the FBI opened its investigation of potential coordination between Russia and the Trump Campaign a few days later based on the information."
This came soon after British and European intelligence agencies told their US counterparts about communications they intercepted between Trump associates, Russian officials and other Russian individuals during the campaign.
Since Trump won the election, British and American intelligence officials have insisted they continue to work together as closely as ever, despite the tumult at tops of their leadership. But Trump's disregard for the intelligence community has strained ties with some of its strongest partners.
Yet at the same time, Trump has repeatedly perpetuated baseless accusations of spying against critical allies. Specifically, Trump has repeatedly alleged -- without any evidence -- that the Obama administration wiretapped him during the 2016 presidential campaign with the help of a British spy agency.
A former senior US official pointed to the President sharing highly classified intelligence about ISIS obtained from Israel with Russia's foreign minister and US ambassador during an Oval Office meeting in May 2017 as an example of Trump's casual attitude when it comes to protecting sensitive information.
"Going all the way back to that point we've seen strains in the intelligence sharing relationship we have within the Five Eyes community," the former official said. "I have not seen these types of strains in our relationship since the immediate aftermath of the  Edward Snowden revelations."
That added pressure is particularly problematic when the intelligence concerns Russia, as it does in the Barr review, the former official added. "Intelligence related to Russian activities and influence around the world is through not only our own collection but comparing what we gather with what our other Five Eyes partners are gathering."
On Capitol Hill, Democrats have blasted the President's decision to declassify the pre-election intelligence.
House Intelligence Committee Chairman Adam Schiff accused Trump of "conspiring to weaponize" classified information while Senate Intelligence Committee Ranking Member Mark Warner told CNN that the move "has the potential to jeopardize" key relationships with foreign partners.
"Trust and confidentiality are essential aspects of our partnerships with foreign intelligence services -- and the President's bizarre decision to allow the Attorney General to selectively and unilaterally declassify information certainly has the potential to jeopardize those relationships," Warner said.
CNN's Marshall Cohen and Laura Jarrett contributed reporting
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