Almost half of householders in a trial of the Green Deal grant rejected the scheme, despite promised long-term savings.

A Department of Energy & Climate Change (DECC) spokesperson said: “The PAYS pilots reveal there is significant demand from householders for installing major energy efficient home improvements such as solid wall insulation when householders are helped with the upfront costs.  

"However, these pilots only tested some elements of Green Deal, key features like repayment through energy bills and the ability to pass costs on when moving home will only be possible once legislation has passed. Green Deal will therefore be a decisive step forward in helping households finance energy efficiency improvements.”