OPPOSITION Leader Tony Abbott has been too busy "doing very important things" in England to have read the week-old judgment dismissing a sexual harassment claim against former speaker Peter Slipper.

Federal Court judge Steven Rares found Mr Slipper's accuser James 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.

Despite not having read the 76-page judgment Mr Abbott said he was confident his former cabinet colleague had "acted rightly at all times".

"Mal is a friend of mine," he told reporters in London overnight.

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

Mr Abbott also said he looked forward to campaigning with Mr Brough, who is the LNP candidate for Mr Slipper's seat of Fisher.

When asked why he hadn't yet read the judgment, the opposition leader said: "Because I am doing very important things for the people of Australia here in this country right now."

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

He is due back in Australia tomorrow.