A court fight is brewing between Federal Attorney-General George Brandis and his Labor counterpart Mark Dreyfus over access to his electronic ministerial diary.

In March last year, Mr Dreyfus lodged a Freedom of Information (FOI) request for access to Senator Brandis' diary, contained in his email program.

He was seeking a print-out of all the diary entries, including notes of his meetings and appointments for the period from September 18, 2013 to March 27, 2014.

But his request was denied by Senator Brandis's chief of staff, Paul O'Sullivan.

The grounds for the denial was the "practical refusal reason" that giving access to the documents would "substantially and unreasonably interfere with the performance of the Minister's function".

"Today I will be challenging Senator Brandis's refusal to release his ministerial calendar of appointments under FOI in the Administrative Appeals Tribunal," Mr Dreyfus said.

"Senator Brandis has taken an unnecessarily obstinate approach to what should be a routine request. He refuses to release any part of his calendar.

"FOI is a vital tool for maintaining transparent, accountable government. Australians have a right to know what the Government is doing."

Mr Dreyfus argued key policy decisions have been made while Senator Brandis has held the office and "[Australians] have a right to know what senior Government ministers are doing with their time, who they're meeting with, who they're being lobbied by".

"Senator Brandis thinks he's above the rules. He has no interest in accountability," Mr Dreyfus said.

"His own officials have admitted that they play 'hardball' on FOI and he has slashed funding to the FOI watchdog and plans to abolish it altogether."

'Brandis would need 40 hours to accommodate request'

Letters between Senator Brandis and Mr Dreyfus's offices, provided to the ABC, outline an at times terse argument between the two camps.

Mr Dreyfus, a Queens Counsel and who the ABC understands will be representing himself at the tribunal, wrote that the claim producing the documents would interfere with the Attorney-General's work was "extreme".

"There is no reason why the task of locating relevant calendar entries and printing a copy of them could not be delegated to a departmental officer of junior ministerial office staff," Mr Dreyfus wrote.

"Indeed, anybody with the most rudimentary IT skills would be capable of performing this basic function."

Mr Dreyfus argued all he was after was a week-by-week print-out of the diary.

It was an assertion the Attorney-General's office strongly denied, citing Senator Brandis would have to be personally involved in considering which diary entries could be disclosed.

"The office of the Attorney-General estimates that a hard copy print-out for the relevant period would be about 220 pages long and contain approximately 2,400 separate appointment entries," Mr O'Sullivan wrote in reply.

"Your request would therefore, on a conservative view, engage the Attorney-General for at least 40 hours.

"It would also likely engage senior ministerial advisers, and other staff, for a considerable period of time."

Mr Dreyfus's office pointed to another case to argue in favour of opening up the diary, involving current Minister for Territories, Local Government and Major Projects, Paul Fletcher.

In 2013, Mr Fletcher was seeking access to the calendar of then prime minister Julia Gillard.

But the Attorney-General's office said Mr Fletcher's request was more narrow and easier to accommodate, and did not fit with the current dispute.

Senator Brandis's office declined to comment, saying the matter was before the courts.