WASHINGTON (AFP) - US President Donald Trump on Friday attacked leaders of his own Justice Department and the FBI as politically biased in favor of Democrats.

   "The top Leadership and Investigators of the FBI and the Justice Department have politicized the sacred investigative process in favor of Democrats and against Republicans," Trump tweeted in the latest example of open conflict with the two bodies.

   The message came as Trump was expected to approve the release of a confidential Republican-drafted memo alleging abuse of authority in the FBI's probe of his election campaign and its ties to Russia.

   Democrats and critics in the intelligence community say the release is a stunt, using very selective information that cannot be countered publicly without revealing more secrets about government counterintelligence operations.

   They say the ultimate goal of the memo, with Trump's support, is to undermine special counsel Robert Mueller's investigation into possible collusion between the Trump campaign and Russia, which has edged closer to the president himself, and possible obstruction of justice.