US President Donald Trump's former national security adviser Michael Flynn pleaded guilty to lying to the FBI on Friday (1 December) and Twitter is mercilessly trolling him over it. In a dramatic development in special counsel Robert Mueller's probe into Russian interference in the 2016 election and possible collusion between Trump's team and Moscow, Flynn has agreed to cooperate fully with the investigation as part of his plea agreement.

He could face up to five years in prison over the charge.

Flynn is the first official that held a formal position in the Trump administration to be charged in the Mueller probe.

After news of the guilty plea broke, Twitter erupted with a myriad of comments, memes and jokes in response with many saying it represents a significant move for Mueller and brings the probe directly into the White House.

"The Special Counsel's investigation has breached the White House gates, reaching one of Pres. Trump's most trusted confidants and unmistakably implicating other top officials," Senator Richard Blumenthal tweeted.

"Make no mistake, #Flynn's betrayal of national security is an enduring black mark on our country's history and a stunning violation of his oath of office. Incredibly, he lied to the FBI while he was the President's chief national security adviser."

One person tweeted: "499: Number of days between when Michael Flynn led a 'Lock her up!' chant at the 2016 Republican Convention and pleading guilty of lying to the FBI."

With Christmas around the corner, many creatively came up with a few holiday carols using the hashtag #TrumpCarols to poke fun at the president in light of the news.

Others noted that Trump has yet to tweet about the latest development in the investigation.

"Notice @realDonaldTrump hasn't tweeted about #Flynn getting caught? He's panicking right now, jail time is coming!" one person tweeted.

Actress Tara Strong tweeted: "Just wondering how much longer the #WhiteHouse staff can keep @realDonaldTrump's phone hidden."

"What is happening now in the White House is exactly what you should expect when you elect a President that says 'I use the best words'," one user said.

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Twitter is furiously trolling President Trump in light of Michael Flynn's guilty plea JIM WATSON/AFP/Getty Images