The leader of the Democratic Unionist Party apologised yesterday for her mistakes and failings in the botched green energy scheme that led to the collapse of the Northern Ireland Assembly.

Arlene Foster, the first minister, was enterprise minister in the power-sharing executive and introduced the Renewable Heat Incentive (RHI) scheme in 2012. She admitted that she brought in the “cash for ash” scheme without reading the technical details and realising what a risky venture it was.

RHI was on course for a multimillion pound overspend and alarm bells were ringing at the Treasury when it was closed down in 2016.

Farmers and businesses had been rushing to join up when they realised that they could get £160 for every £100 they spent on fuels