Washington, Jun 19 (IANS): The Trump administration is making a last-ditch effort to stop the publication of a damaging new book by a former national security adviser.

Among several allegations, John Bolton said Donald Trump "pleaded" for help from China to win re-election in 2020.

The Justice Department has filed an emergency order seeking to block the release on national security grounds, the BBC reported.

Constitutional experts said the move is unlikely to succeed and US media have already published extracts.

The new work - The Room Where It Happened - is due to go on sale on 23 June. In it, John Bolton paints a picture of a president whose decision-making was dominated by a desire to win the presidency again.

Many of the allegations are based on private conversations and are impossible to verify. The Trump administration has pushed back against Bolton, with the president saying the book was "made up of lies and fake stories".

"Many of the ridiculous statements he attributes to me were never made, pure fiction," Trump tweeted on Thursday, adding: "Just trying to get even for firing him like the sick puppy he is!"

Despite this, Bolton's book has been keenly anticipated, given his formerly high-ranking status as the president's top adviser on security matters.

Late on Wednesday, the Justice Department asked a judge for a hearing on Friday to stop the book's release.

The Trump administration argues that publication moved forward before the book could be properly vetted.

The work "still contains classified information," the Justice Department wrote in filing. "This means it contains instances of information that, if disclosed, reasonably could be expected to cause serious damage, or exceptionally grave damage, to the national security of the United States."

The White House filed another lawsuit earlier in the week against Mr Bolton on similar grounds.

Publisher Simon & Schuster rejected the allegations, calling the filing a "frivolous, politically motivated exercise in futility".

Ben Wizner of the American Civil Liberties' Union wrote that any bid to halt its release was "doomed to fail".

"As usual, the government's threats have nothing to do with safeguarding national security, and everything to do with avoiding scandal and embarrassment."