An ambitious energy saving scheme that could save families up to £600 a year and negate the need for mass fracking is being launched today by Unison.

Ahead of the launch, the union reported yesterday that Britain’s energy crisis will leave it dependant on imports for 70 per cent of gas resources within just five years.

The coalition is responding to the looming crisis with a plan to let fracking firms run gas lines to 400 wells through land without permission.

But Unison has drawn up a green alternative to be launched at its energy sector conference in Brighton today.

The union's scheme prioritises giving an energy-saving makeover to the 15 per cent of homes with leaking roofs, damp walls and rotten windows which could cut family fuel bills by £300-£600 a year.

General secretary Dave Prentis said: “The UK’s energy supplies have reached crisis point and the government must take action to bring millions of households in from the cold.

“Unless the government invests in a long-term strategy to preserve our dwindling North Sea gas supplies, we will be relying on expensive imported energy and wide scale fracking for shale gas.”

Low income households would receive remedial work, capped at a maximum of £10,000, for free while others should benefit from a 10-year interest free loan under the plan.

The Tory alternative will leave Britain at “the mercy of international markets by increasingly relying on imported gas supplies.” Mr Prentis added.