The federal government has finally signed off on the first stage of light rail to Woden.

Stage 2A of the project was approved yesterday afternoon, with conditions imposed to protect the endangered golden sun moth.

Meanwhile, the ACT Government will spend 2.1 million dollars to raise London Circuit, with construction to commence as early as this year.

The project will raise the London Circuit road level on either side of Commonwealth Avenue.

It should take around two years to complete.