The tunnel would house power cables to connect a planned nuclear power station in West Cumbria to the grid.

The power giant will start a major consultation exercise with local communities across Cumbria and Lancashire in September to outline its plans.

National Grid Project Manager Robert Powell said: “The discussions we’ve had over the course of several years have given us invaluable information which has helped us develop and refine the options for connecting new power generation into our network.

“We’re now at a crucial stage of our project. We’re getting ready to share with local communities all the work that we have done to date and to seek their views on our findings including what we have identified as our ‘emerging preference’ at this point.

“We promise to listen, to learn from what we hear and then to seek to develop the project in a way which achieves a balance between meeting our country’s future energy needs and protecting the very special landscapes it touches upon.”

For full details of the scheme click here