The cost of the National Bicentennial Science Centre was estimated to be $14 million, ministers were told in December 1985.

The construction of the iconic building would add to the likely peak of activity. ''The construction industry in the ACT is experiencing boom conditions,'' they were told.

The building industry was dominated by major projects - Parliament House, the Australian Defence Force Academy, the Prime Minister and Cabinet building, the National Museum, the Australian War Memorial's aircraft hall, the Canberra aviation college, the Health National Biological Standards Laboratory and a commonwealth office block in the Tuggeranong town centre.

The deregistered Builders Labourers Federation had 3000 members in the ACT and ministers were told to expect severe industrial unrest.

''There have been reports of deals between unions and contractors and subcontractors to restrict competition and force up subcontract prices,'' one submission to cabinet said.

''These reports include a union-enforced restriction on the number of concrete trucks operating in the ACT and BLF-inspired 'agreements' covering steel fixing, concrete placing and testing, mobile crane operators, scaffolding, bricklaying and asbestos removal.

''Overheating in the ACT building and construction industry has been and continues to be a major factor contributing to the level of industrial disputation in the local industry.

''A very tight labor market has placed building unions in the ACT in a strong bargaining position and building unions have not been loath to take advantage of that situation.''

Ministers were told there were close links between the BLF and the ACT Trades and Labour Council.

>> Questacon, Australia's National Science and Technology Centre, was officially opened by then prime minister Bob Hawke in November 1988.