Former national security adviser Michael Flynn pulled out of a campaign event that was supposed to be held Sunday in support of Troy Downing, a Republican candidate contesting the U.S. Senate seat for Montana.

"Unfortunately, @GenFlynn will no longer be able to come to Billings due to a family emergency. We are going to cancel the rally scheduled for tomorrow, Sun., May 6," Downing, a businessman and U.S. Air Force veteran, wrote on Twitter Saturday.

"@GenFlynn supports our campaign, he knows I have the best chance to defeat Jon Tester!" he continued, referring to the Democratic incumbent.



Unfortunately, @GenFlynn will no longer be able to come to Billings due to a family emergency. We are going to cancel the rally scheduled for tomorrow, Sun., May 6. @GenFlynn supports our campaign, he knows I have the best chance to defeat Jon Tester! https://t.co/huIheGfB4P — Troy Downing - U.S. Senate (@TroyDowningMT) May 5, 2018



In an accompanying video, Flynn reiterated how he "strongly and wholeheartedly" endorsed Downing ahead of the Republican primary on June 5 against three other Republican contenders.

Flynn also lashed out at Tester, the ranking member of the Senate Veterans Affairs Committee, over his handling of former VA secretary nominee Ronny Jackson. Jackson withdrew his nomination to lead the second largest federal agency on April 26 after unverified reports about being drunk on the job, overprescribing pain medication, and creating a hostile work environment.

Flynn resigned in February 2017 amid reports he had misled Trump administration officials about his communications with Sergey Kislyak, the Russian ambassador to the U.S., before President Trump's inauguration.

In November 2017, Flynn pleaded guilty to lying to the FBI after being investigated as part of special counsel Robert Mueller's Russia investigation.