The project is on track, with power for the Olympic Park to switch from overground to underground later this year.
Two six kilometre tunnels have been dug beneath the Olympic Park, to run the power needed for the Games and the legacy site after 2012.
Overhead powerlines which run across 52 pylons in the Park still need to be removed. The tunnels were finished last year, the first Olympic Park construction project to be completed.
More than 200km of electrical cables will be installed in the tunnels – enough to stretch from London to Nottingham. Cable installation work in the first tunnel has been completed, and cabling works are also now well underway in the second tunnel. Around 150km of cabling has now been laid in total bringing the project up to the three-quarter mark stage.
"The delivery of the powerlines project is vital in 'unlocking' the Olympic Park site as we prepare for the start of construction of world class venues and infrastructure later this year," said ODA Chief Executive David Higgins.
"Completing the powerlines tunnels last year was an important achievement but on a project of such scale and importance it is vital that we continue to hit key targets. The significant progress we are making to create a brand new electrical infrastructure within the tunnels keeps us on track to hit further milestones ahead of the Beijing Games this year."
The installation of monitoring and ventilation equipment is also now complete in one of the tunnels, with installation work now beginning in the second tunnel. More than 9,000 brackets have also been installed to carry cabling along the tunnel walls.
Running power cables undergorund in second in the Olympic park's ten 'Milestones to Beijing', due to complete before the Beijing games later this year.
Once cabling work is complete, power can be switched to the underground supply and the overhead pylons dismantled towards the end of 2008.