With eyes fixed on seven NCA executives including chairman Don Aitkin and chief executive Gary Rake at a public forum, Mr Powell said it was time to shine a light on the issues confronting Canberra.

''In 20 years you have been dismal failures, you have to face up to that,'' he said.

The Commonwealth had abandoned the national capital, which was dying and was not in the minds of Australians as it was 20 years ago.

''All the NCA is now is an undertaker, it builds a few memorials every now and then.''

Mr Powell said massive developments under way in NSW would further erode Canberra's standing as the national capital.

Professor Aitkin said across Australia the notion of having a national capital had faded.

Overseas, people thought Sydney was the national capital and it was true, the NCA would love to have more money to lift the city's standing.

At its first ever public forum the NCA promised a more collaborative approach to planning, admitted mistakes in consultation and to being short of money.

Mr Rake told The Canberra Times Mr Powell was passionate about Canberra but from a different era, when one body controlled all the territory's planning.

Had the NCA been starved of money?

''We've put it on record that our maintenance budget has not kept pace with inflation.''

Lack of consultation over proposals to redevelop the Albert Hall precinct, a new pedestrian bridge across Lake Burley Griffin and a surprisingly big, $600 million headquarters for ASIO dominated the meeting.

Professor Aitkin said while the NCA would try to be more open it was the guardian of the national interest and the Commonwealth's decisions would prevail.

Campbell resident Mark Anderson said this implied a one-way street, where the national interest railroaded the local interest.