MARTIN McGUINNESS quit as Northern Ireland’s deputy first minister yesterday, collapsing the power-sharing government.

The Sinn Fein MLA resigned over Democratic Unionist Party (DUP) First Minister Arlene Foster’s refusal to step down over the “ash for cash” Renewable Heat Initiative (RHI) scandal.

Stormont faces shelling out £490 million over the next 20 years to subsidise businesses that have installed eco-friendly heating systems because tariffs were set too high and no cap set.