Bishop defends Monis letter time delay

Foreign Minister Julie Bishop has defended the time it took for the parliamentary record to be corrected over the failed delivery of a letter from the Sydney siege gunman to a high-level review.

A Senate hearing on Tuesday night was told the Department of Prime Minister and Cabinet informed their colleagues at the Attorney-General's department it hadn't received the October 2014 letter on June 1, but the error wasn't made public in parliament for three days.

"The record was corrected at the earliest opportunity after receiving formal confirmation from the secretary of the Attorney-General's department," Ms Bishop told question time on Wednesday, after being asked for an explanation from Labor.

Labor failed in an attempt to censure Ms Bishop, the prime minister and attorney-general for failing to correct the record at the earliest opportunity.

Opposition frontbencher Tony Burke also claimed the foreign minister misled parliament again on Wednesday.

"This is a cover-up of a cover-up," opposition foreign affairs spokeswoman Tanya Plibersek said.

Earlier, Tony Abbott said it was "simply fanciful" that somehow more attention to the Monis letter would have prevented the Martin Place siege.