The consortium building the first stage of Canberra's light rail network would have accrued $179 million in debt by the time of the election, according to Treasury advice.
The ACT government has released more detailed Treasury advice of the estimated cost of tearing up the light rail contract under the "termination for convenience" clause.
Treasury overall estimates cancelling the contract would cost a total of between $223 and $241 million by the end of October, or between $258 and $276 million by the end of November.
Paying back the debt incurred by the consortium at the time of the election accounts for by far the largest chunk of that total.
It is estimated that the debt, financed mostly by six banks, would be $179 million by the end of October and $206 million by the end of November.
The level of debt corresponds closely to the amount actually spent on the project by the consortium, which has been taken from the project agreement, a document setting out how the project will be delivered, and how much will be spent at each stage of the project. That level of detail remains commercial-in-confidence and has not been released.
The money that would have been spent by the election includes early construction costs, design work, deposits on the vehicles, legal fees, the costs of the bid, creating the consortium, due diligence work, and planning.
The ACT government says it has not inflated the level of debt in any way, and that such costs were normal in the early stages of a major infrastructure project.
The fair value of consortium's equity is also estimated to add another $19 to $33 million to the termination cost.
An estimate of the expenses the consortium would have incurred, but not yet paid, adds another $27 million by the end of October and $34 million by November.
The financial break costs, designed to compensate banks for any loss of profit, would either cost $16 million or give a windfall of $16 million, depending on the difference of the interest rate at the time of breaking the contract to that at financial close in May.
University of Canberra infrastructure financing expert Professor Cameron Gordon said that "termination for convenience" clauses were now becoming standard in major projects of this kind.
Professor Gordon said the termination clause for the light rail project appeared to be standard, or "boilerplate", although it was difficult to assess without seeing the entirety of the contract, including a key schedule that has not been made public.
He said the level of project debt cited by the Treasury appeared to be "plausible", but said the assessment was very difficult without seeing commercial-in-confidence information or having anything to easily compare it to.
But he said the level of debt may not necessarily all present a cost to the incoming government.
"If proceeds are collected but very little spent this is not necessarily a cost," Professor Gordon said.
"The bonds could be liquidated and proceeds returned to bondholders - assuming the indenture allows this," he said.
"Or the government takes on the liability but also presumably takes on the proceeds and now without a light rail to spend it on so it could spend it on something else."