Working with its sister multi-utility contractor Instalcom, the group will decommission 44kms of oil-filled EHV cable circuits and associated plant within the Greater London area.

The project is understood to be worth up to £30m and is scheduled to start in January.

It will involve key stakeholders including Network Rail, several London Boroughs, and the Canals River Trust.

O’Connor Group was selected due to its extensive experience of managing the installation and removal of power assets in dense urban locations.

O’Connor Group CEO Tim O’Connor said: “We are delighted to be supporting National Grid in the safe and successful delivery of this strategically important asset decommissioning programme and we hope to utilise this project to develop greater intelligence and hopefully new techniques which are expected to have a positive impact on cable fluid loss.”

Project lead from National Grid, Chris Shelton, said, “This is a major project and with the support from O’Connor Group, we will work to minimise the impact of our essential works on the local community and environment.

“We are able to leave the cables that need decommissioning in the ground. This will avoid major disruption to the capital as we do not need to dig up long stretches of the road network.

“Instead we will be removing the oil from the cables which will have a positive impact on the local environment.”