Opposition Leader Tony Abbott is not happy about the prospect of losing a Coalition spot on a high-powered parliamentary committee on intelligence to make way for independent MP Andrew Wilkie.

AM has been told Prime Minister Julia Gillard wrote to Mr Abbott to inform him that only three Coalition MPs will sit on the committee instead of the four he had nominated.

This is because Ms Gillard has offered Mr Wilkie - the Tasmanian independent who helped her form minority government - a position on the committee, which is usually held by an Opposition MP.

The prospect of Mr Wilkie's presence on the nine-member Parliamentary Committee on Intelligence and Security, which reviews the operations of Australia's most secret agencies, has raised eyebrows.

The independent MP rose to prominence when he spoke out against the Howard government and quit the Office of National Assessments just before the Iraq invasion in 2003.

Dr Michael McKinley, an expert on terrorism, strategy and intelligence at the Australian National University, says it is a surprising proposal.

"It's an interesting and probably just a little bit surprising suggestion if it comes about," he said.

"I think it's also possible to conclude that it's a proposal that has some merit, given the recent history of Australian intelligence."

While MPs are still coming to terms with the idea, Ms Gillard and Mr Abbott have been engaged in a ping pong game of correspondence.

Last week Mr Abbott wrote to nominate four Coalition MPs.

AM has been told the Prime Minister wrote back yesterday saying the Government will appoint five Labor politicians plus Mr Wilkie, which means the Coalition loses one appointment on the nine-member committee.

Last night Mr Abbott fired off another missive, objecting to the cut.

But Dr McKinley predicts Mr Wilkie will make a difference.

"There is a tendency for such committees to become creatures of the intelligence organisations themselves, to become far too cosy with it," he said.

"I think Andrew Wilkie's instincts and certainly his track record suggests that that is one temptation which he might be spared."

Mr Abbott has not objected to Mr Wilkie's appointment, but he argues his membership should not be at the expense of the Opposition, suggesting the Government amend the Act to expand the committee by one.

"If the Prime Minister wants to put Mr Wilkie on the committee that's her business, but she certainly has no right to reduce the Coalition's representation on it," he said.

"I've made the point Mr Wilkie is effectively a government member and if she wants him on the committee then let him be part of the Government's representation."

There are also murmurings Mr Wilkie's presence may inhibit the operation of the committee because some in the intelligence agencies, who take a dim view of him quitting the Office of National Assessments and speaking out, would be "less generous" in sharing information informally.