The ACT government was negotiating the controversial sale of a Dickson carpark to the Tradies Club Group as early as December 2010, up to two years before expressions of interest were called for the sale.
The block of land is one of three that were part of a controversial land swap deal in Dickson between the government and the union-linked club in late 2014.
That deal is now under investigation by the territory's Auditor-General, one of two current probes into deals undertaken by the now-defunct Land Development Agency, the other focussed on rural land purchases.
The land swap is likely to be a key focus of the Opposition during debate scheduled for Thursday in the Legislative Assembly on leader Alistair Coe's motion of "no confidence" in the Chief Minister, Andrew Barr.
But Mr Coe's motion is likely doomed to defeat, given the key votes he needs come from the Greens, which as part of its power-sharing deal with Labor, have agreed not to support any such a motion this term that does not prove corruption, gross negligence or ministerial conduct breaches.
While the LDA's deal for the club to buy the 5300sqmt carpark was sealed in December 2014, as part of a wider government call for "expressions of interest" to buy the block in 2012, the club was seeking the block in late 2010.
The government requested a valuation from MMF on block in November 2010, which was completed the following month.
That valuation put the block at $2.5 million at the time, on the basis of building a two-storey development, given the then height restrictions of two storeys, and need to replace 134 car parks on the site.
In the document, valuers wrote that "the Canberra Tradesmen's Union Club are negotiating the purchase of the land to enable substantial redevelopment and replacement of the club facilities".
"We approached the valuation assuming the carpark as a development site rather than a car park as it is to be used by the Tradesmen's Club to extend their facilities and would be sought as a development site in the open market place subject to approval," it reads.
It also referred to proposed changes to the Dickson precinct code at that time, detailed in a report on the area's plans and design framework, which showed "much proposed changed for the precinct in which the subject is located".
"The report illustrated dramatic changes to height limits which could take the current sites limit of two storeys to six storeys subject to the upper floors being residential," it reads.
"For the purpose of this report we have adopted current planning policies with the precinct code for these changes in excess of two years from effect."
The same firm later valued the block at $3.18 million, excluding GST, based on building a six-storey building on the site.
In 2014, the government called for expressions of interest for the purchase, to which the club offered the top price, $2.4 million in late 2014, before entering negotiations.
Ultimately, the club bought the carpark for $3.18 million, excluding GST, that would be paid once another carpark was delivered in the area, as part of the wider deal involving two other blocks in the area.
The government retained control of the Dickson carpark and its revenue, with the Tradies unable to build there for five years, and the club agreeing to pay almost $1 million more than they had tendered in 2012.
Clarification: An earlier version of this article said the Greens-Labor parliamentary agreement would not allow the minor party to vote for a no confidence motion. It does, if corruption or other criteria are met.