The consortium building Canberra's billion-dollar light-rail project has failed to meet all but one of its delivery targets this year.

The ACT Government has been forced to push back completion dates in five areas, including the laying of track and construction of the stops at each end of the line.

"Dynamic testing", which was supposed to begin in February, only started this month.

Four indicators set for completion by the end of the financial year remain unfinished, including the construction of a maintenance and control centre.

That building was slated for completion in March, but its revised target date has blown out five months, to August.

The only target the consortium was able to meet was the arrival of the first light-rail vehicle, which was constructed by Spanish firm CAF and shipped over in December last year.

Despite the delays, Transport Minister Meegan Fitzharris said the project was still on track to begin operation this year, and that the revised target dates had no implication on the contract between the ACT Government and Canberra Metro.

"There are always changes to key milestones when undertaking significant infrastructure projects on the scale of the light rail network," she said.

"However, the Government has been assured by Canberra Metro that the most important date — the completion date, is still planned for the end of 2018 — as reflected in the budget papers."

The ACT Government insists the light rail will be done by the end of the year. ( Supplied: Canberra Metro )

'I don't have those off the top of my head'

Light-rail stage one project manager, Meghan Oldfield, reiterated Ms Fitzharris' comments that the movement of target deadlines in a project this size was "not uncommon".

However, when asked what targets had moved, she said, "I don't have those off the top of my head".

Ms Oldfield said the ACT Government still planned to complete the project in December, and no additional money would be spent to achieve this.

"The territory won't expend any funds until it's in operation... our schedule isn't blowing out and also the way that the contract works is we don't have any payments until the first passenger is on board," she said.

"There's no specific date scheduled at the moment because with the testing and commissioning process and going into weather periods like this there will be things that could change a bit.... [there] are testing, commissioning or accreditation periods which have a degree of movement to them... but we are planning for the end of the year."

The Government said the price for taxpayers was fixed, so any additional costs related to delays in stage one of the project would be worn by the consortium.

Seven trams of the 13-vehicle fleet have arrived in Canberra.