First Minister facing repeated calls to step aside after letter of 'guarantee' to banks emerge

Arlene Foster's pledge to claw back millions committed to the RHI has been questioned by rivals

UUP leader Mike Nesbitt says Arlene Foster must stand down.

A pledge by the First Minister to claw back millions of pounds committed in a botched energy scheme has been questioned.

It's emerged she told bankers that payments would be guaranteed.

In a letter to Northern Ireland's leading banks at the outset of the RHI, Arlene Foster said the state-funded eco-subsidies offered applicants a "good return on investments."

Fatal errors in the incentive have left Stormont facing a potential £490-million overspend bill over the next twenty years.

Mr. Nesbitt has been speaking to Q Radio.

Calls for her to step aside have been brought by SDLP leader Colum Eastwood, Sinn Fein's Michelle O'Neill and Conor Murphy, -and TUV leader Jim Allister.

Meanwhile, Economy Minister Simon Hamilton has defended the DUP leader.

He accused opposition MLAs attacking the DUP leader of offering nothing more than "party political attacks and resignation calls".