Artist's impression of the proposed Canberra light rail.

ON TRACK: An artist's impression of the ACT light rail. Photo: Supplied

ACT government figures show the staff bill for Canberra's light rail project will soon hit $45,000 a week now that the hunt is on for an executive to stop the project's cost from blowing out.

The present weekly wages bill for Capital Metro is at least $37,373 but will rise when the government fills another four positions - including the role of finance and economics director - which will take the total staff number to 17.

The soon-to-be filled $230,406-a-year job of director of finance and economics involves providing the ''prosecution of an agreed financial strategy in the negotiation of delivery agreements'', according to the job advertisement.

The person who fills the role will spend a lot of time liaising with the directorates of the Chief Minister and Treasury and have the option of signing a contract of up to five years. The government is also paying economic and commercial advisors from Ernst & Young and an Arup-led consortium, which includes six local specialist consultants to provide technical advice and who will help with the preliminary design of the $600-million line between Gungahlin and the city.

The tender selection process to find a group to construct and operate the light-rail system will start in 2015 and a government spokesman said the project was still on track to start in 2016. ''Later this year they will produce a design definition for the project, select the best funding model and define the best approach to building and operating the light rail system,'' he said. The top three paid positions at Capital Metro will be director Emma Thomas, who is on a $382,000 annual package, her deputy (about $240,000 a year) and the $230,406 role of executive director of procurement and delivery.

Separate to staff costs, the chairman of the Capital Metro Project Board, John Fitzgerald, is listed as receiving $71,000 a year for his work.

Opposition transport spokesman Alistair Coe said the light rail was an expensive strategy Labor used to get the Greens - whose sole MLA Shane Rattenbury, holds the balance of power - to keep them in government.

"Only now is the master plan being done, long after the government announced the route between Gungahlin and the city,'' Mr Coe said. ''How then is the master plan supposed to effectively determine the best possible rollout of the network?''