Last Wednesday, Federal Court Justice Steven Rares dismissed a sexual harassment claim by Mr Slipper's former staffer, James Ashby, saying the matter was an abuse of process with the main purpose of pursuing "a political attack" on the member for the Queensland seat of Fisher.

Justice Rares also found Mr Ashby acted "in combination" with another staffer, Karen Doane, and Mal Brough to advance the interests of the former Howard government minister and the Queensland Liberal National Party.

But speaking overnight from London, Mr Abbott told the ABC TV that he had not read the judgment, explaining he had been doing "very important things for the people of Australia, here in this country right now".

Despite not having read the judgment, Mr Abbott said he was confident Mr Brough - who is the LNP candidate in Fisher - had acted "rightly at all times".

Mr Abbott added that Mr Brough was a friend and a past colleague.

"I look forward to having Mal as a colleague of mine again."

During his trip, Mr Abbott delivered a speech to his old college at Oxford University and met with a number of officials including British Foreign Secretary William Hague, Mayor of London Boris Johnson and the outgoing Governor of the Bank of England, Sir Mervyn King.

Mr Abbott's office has confirmed that the Opposition Leader has been briefed on the judgment.

Trade Minister Craig Emerson said Mr Abbott's concession that he had not read the judgment was a "damning indictment on a man who puts himself forward as the alternative Prime Minister of Australia."

Dr Emerson said Mr Abbott was "too lazy" to read the judgment, that has a seven page summary.

"It is clear that Mr Abbott does not read documents that are essential for the discharge of his duties as Leader of the Opposition," he told reporters in Sydney on Wednesday.

"The only document that we know Mr Abbott has read this year is 50 Shades of Grey."

Deputy Opposition Leader Julie Bishop told The National Times on Wednesday that she read the judgment on the day it was handed down.

Ms Bishop noted that at the time, she was acting Opposition Leader as Mr Abbott was overseas.

She also noted that shadow attorney-general George Brandis has been travelling with Mr Abbott in Britain.

"I assume George and/ or [his] advisers have briefed him on it," Ms Bishop said.

Last week, Prime Minister Julia Gillard called on Mr Abbott to "come clean" about what he knew about the Slipper saga. Ms Gillard said Mr Abbott had to stop using "weasel" words over the matter and disendorse Mr Brough.

At the time, Mr Abbott said Labor should accept there was no conspiracy and that the federal government should stop "hyperventilating".

This is not the first time Mr Abbott has said he did not read a key document.

In August, BHP announced it was shelving plans for a $30 billion expansion of the Olympic Dam uranium and copper mine in South Australia.

Mr Abbott blamed the carbon price and the mining tax, although BHP cited neither as a reason in its statement explaining the decision.

That night, on the ABC's 7.30 program, Mr Abbott said "no" when asked if he had read BHP's statement

The next day, he said he had mis-answered the question, and had read the statement.

With AAP