Where Britain’s journey to insulation went wrong

Conservative governments have left the UK's problem with leaky homes unresolved

• Labour says it will insulate 2m houses in first year

Christmas 2015 was a miserable one for the 1,000 employees of Leicester-based Mark Group who had lost their jobs with the energy efficiency company just weeks before.

The business, named Britain's fastest-growing in a prestigious list published just two years earlier, had become a casualty of then prime minister David Cameron's environmental flip-flopping, which saw him oscillate from hugging a husky to issuing a pledge to cut the green crap".