Donald Trump has effectively accused the UK of spying on him just 24 hours after his State Visit to London was confirmed.
The US President is set to visit the UK from June 3-5, for an official State Visit, following his working visit last year.
But this morning he tweeted a claim about British Intelligence agents helping the Obama Administration to spy on his presidential campaign in 2016.
The US President quoted a story from right wing news channel One America News Network, which has been widely accused of spreading false conspiracy theories.
He wrote: "'Former CIA analyst Larry Johnson accuses United Kingdom Intelligence of helping Obama Administration Spy on the 2016 Trump Presidential Campaign.' @OANN
"WOW! It is now just a question of time before the truth comes out, and when it does, it will be a beauty!"
In the US, Johnson, who left the CIA more than 26 years ago, is viewed as a deeply controversial character.
He is known for best known for spreading a hoax in 2008 that Michelle Obama had been videotaped using a slur against white people.
He also said Osama Bin Laden wasn’t a real threat two months before 9/11 attack.
In 2013, Johnson falsely accused John Kerry of war crimes in Vietnam
A GCHQ spokesman said: "As we have previously stated, the allegations that GCHQ was asked to conduct 'wire tapping' against the then President Elect are nonsense. They are utterly ridiculous and should be ignored."
The tweet came less than 24 hours after Buckingham Palace confirmed President Trump would visit the UK in June as the guest of the Queen.
The US President and First Lady Melania Trump will visit the UK from June 3-5 in the run up to the D-Day anniversary commemorations, it was confirmed today.
But refurbishment work at the Palace means there will not be enough room for the President and his entourage to stay there during the visit.
The GCHQ conspiracy theory has been bubbling around the Trump administration since the early days of his presidency.
Trump’s tweet comes two years after America was forced to make a humiliating apology to Britain after the White House accused GCHQ spooks of helping Barack Obama spy on Trump.
At the time furious UK intelligence chiefs issued an unprecedented denial after the President’s then-mouthpiece, Sean Spicer, cited false claims the Cheltenham-based eavesdropping agency colluded with the former US leader.
It sparked a full-blown diplomatic incident leading to GCHQ bosses to make a rare public statement labelling the claims “utterly ridiculous”.
Spicer had spoken for eight minutes at the White House quoting various news pieces including the words of political analyst Andrew Napolitano, who had appeared on the pro-Trump Fox News on Tuesday.
"[Obama] didn't use the NSA, he didn't use the CIA, he didn't use the FBI, and he didn't use the Department of Justice. He used GCHQ, what is that? It's the initials for the British Intelligence Spying Agency."
Donald Trump WON'T be allowed to stay at Buckingham Palace during UK state visit
GCHQ immediately issued a statement slapping down the claim.
The statement said: "Recent allegations made by media commentator judge Andrew Napolitano about GCHQ being asked to conduct 'wiretapping' against the then president-elect are nonsense.
"They are utterly ridiculous and should be ignored."
In March 2017, Trump’s then-National Security Advisor H R McMaster was forced to contact his opposite number in No 10, the PM’s then security chief Sir Mark Lyall Grant to apologise.
General McMaster also reassured America would never repeat the embarrassment, which threatened to put crucial Trans-Atlantic intelligence cooperation at risk.
Spicer also understood to have apologised.
The Mirror understands Trump forced his spokesman to read out a series of articles which discussed surveillance in an attempt to provide credibility to his unfounded claims.
The claims re-emerged in Fire and Fury, Michael Wolff's book about the Trump White House.
In the book, Wolff claimed Tony Blair had told President Trump that British intelligence services may have spied on him.
A spokesman later denied the claim, calling it "categorically absurd" and "simply untrue."
