The tramline is also set to run past the front door of a building owned by 12 local union and related groups, including the Canberra Tradesmen’s Union Club (run by the CFMEU), teacher unions and the Australian Council of Trade Union’s Canberra wing. That building was granted a change to its lease in 2012, allowing commercial redevelopment.

Among major building owners on the government’s preferred route around the western side of London Circuit and through Barton are Michael Kouper, also owner of the Kingston Hotel, and big names in local property Gerard and Anthony Willemsen, Barry Morris and Graham Potts.

If the government was forced to send the tram over Kings Avenue Bridge instead, an option being explored by a national inquiry, the line would traverse the eastern side of London Circuit and Constitution Avenue. The ACT government has threatened to pull the pin if forced to adopt that route.

Construction-industry-linked superannuation investor ISPT owns no fewer than six buildings on the planned route. On the preferred western side of London Circuit, ISPT owns a building that stretches an entire block at 7 London Circuit and another backing on to it at 18 Marcus Clarke Street. It also owns four large buildings on Kings Avenue and National Circuit, where the tram doglegs to head through Barton, making it one of the biggest owners on the route from the city through Barton.

ISPT was set up by big union and industry superannuation funds Australian Super (ACTU and the Industry Group), HESTA (health) and Cbus (construction). ISPT has two longtime construction union bosses, Frank O'Grady and John Sutton, on its nine-member board. Repeated attempts to contact ISPT for comment were unsuccessful.

Also on the London Circuit doorstep of the tramline is developer Barry Morris, who this year bought the large carpark site and where he plans 1200 apartments.

But Mr Morris, like other owners, said light rail did not play into his decision to buy the block, and would actually bring some restrictions, including advice from planning authorities that he should limit access from London Circuit.

His site was in the city within walking distance of the lake so there was little need for the tram to access the city and other amenities, and he planned a supermarket onsite also.

"So from that point of view, the location of the light rail doesn't come into the equation as it may do on Northbourne Avenue, because we are literally right in the city," he said.

Mr Morris said he was unsure why the government was taking the western route around London Circuit, especially given the extra complexity of getting up to Commonwealth Avenue from that side.

Mssrs Morris and Potts also developed the two large apartment buildings on London Circuit that make up the Metropolitan apartments some years ago, but they are now in private hands.

On the corner of Hobart Place, Peter Sarris and Matt James are building a 200-apartment development.

Mr James said light rail played no part in his decision to develop the Capitol apartments. The site's appeal was in its location opposite the courts and the Reserve Bank, near the ANU and in the heart of the city. But it was possible apartment buyers would use future stages of light rail to travel from their apartment to work in Barton or Woden, he said.

Michael Kouper owns two neighbouring buildings along the rest of that London Circuit block, opposite the city police station, one of which he said was empty. Mr Kouper said he bought the buildings perhaps five or six years ago, was now 83 and had no development plans. He was looking instead to sell, he said.

A few doors down at 13 London Circuit, Jon Tanchevski and Adam Howarth are preparing a development application for a 16-storey hotel to replace their four-storey building. The men, who visited the United States with a government delegation lead by Planning Minister Mick Gentleman in 2016 to look at light rail, are also building the Midtown hotel and apartments on the corner of Northbourne Avenue and Macarthur Avenue.

While Mr Tanchevski has described light rail as the catalyst in Northbourne development, he said he had bought the building before light rail stage one, and likewise bought the London Circuit building this year before knowing stage two would go there.

While none of the property developers claim to be motivated by the tram, they do have much to gain before the line is even built.

A report by the Bureau of Infrastructure, Transport and Regional Economics found light rail boosts property prices an average 9.5 per cent (9.7 per cent for bus rapid transit) - although there was evidence that much of the increase came when projects were announced, and it slowed or even reversed once infrastructure was built.

While many light rail projects levy property owners to help pay and to "capture" some of the value for the taxpayer, the ACT government continues to rule out charging a levy on owners along its tramlines. The Parramatta light rail was to be part funded by a charge of $200 a square metre for apartments in the corridor, and stage one of the Gold Coast light rail was boosted by a $111 levy on land owners, according to a federal report.

A spokeswoman for Transport Minister Meegan Fitzharris said the government had not calculated the expected boost to property values for stage two in Canberra.

"However, there is a general expectation that property values in any light rail corridor may increase as a consequence of people being attracted to living in close proximity," she said.

Asked for details of any representations from or consultation with property owners, the spokeswoman did not provide detail but said, "A number of organisations, landowners and peak bodies representing landowners were involved [in 2017 consultation] and made formal submissions."

She added, "In its ordinary business activities, Transport Canberra has fielded enquiries and met individuals and organisations in many different settings."

Asked whether the government had given any consideration to the question of who owned land on the stage two route, she said the government had considered "ownership and nature of land ownership in the corridor for the purposes of precinct planning and consultation" but the focus had been on a route that worked for public transport and for the community.

The ACT government is touting its tramline as an “urban-renewal land-use solution”, designed to boost development.

It is still trying to argue its preferred route through the federal government. The ACT has already rejected a tram that runs straight up Commonwealth Avenue and around State Circle on to Adelaide Avenue to Woden, instead planning a line that veers off Commonwealth Avenue past old Parliament House to Kings Avenue and from there taking a dogleg up Kings Avenue briefly before turning left on to Windsor Walk.

It runs along Windsor Walk to Canberra Avenue, then turning right to meet Capital Circle. One problem with the plan is that trams can't hold sufficient battery storage to get from the city centre all the way to Adelaide Avenue without overhead wires.

Once the tram passes the four buildings owned by ISPT on Kings Avenue and National Circuit/Windsor Walk, it passes 40 Brisbane Avenue, owned by unions headquartered there, including the Tradies club, run by the CFMEU, and the Australian Council of Trade Unions. A council spokesman said the ACTU and affiliated unions had a long-term investment in the building.

“The ACTU has had no involvement in the planning process for the Canberra light rail. We became aware of the proposed route when your journalist enquired this afternoon," he said.

“We have no plans to alter any of the current arrangements with regard to this property.”

Crossing Brisbane Avenue, it passes the massive RG Casey building housing the Department of Foreign Affairs and Trade, a building owned by MTAA Super, the superannuation fund connected to the motor trades industry. On the other side of the road is 39 Brisbane Avenue, owned by Quintessential Equity, and the Little National Hotel.

Crossing Sydney Avenue, it passes beside 28 Sydney Avenue, owned by Graham Potts; 38 Sydney Avenue, owned by global property giant Blackstone; and 29 National Circuit (1 Canberra Avenue), owned by the Willemsens.

From there it reverts to Capital Circle and Adelaide Avenue, passing residential properties in Deakin and Yarralumla.