Stormont First Minister Arlene Foster has said she will not resign over a failed renewable heating scheme in the North.
The overspending project was designed to encourage businesses to switch from burning fossil fuels to wood biomass heating but has left taxpayers with a bill critics claim could reach £400m.
The DUP leader said she passed on whistleblower concerns raised with her in 2014 to the Civil Service.
She is also seeking to publish details of all those who benefited.
She said: "I will not be resigning. It is political opponents and opponents elsewhere who will always take the opportunity to put out the usual she should resign remark.
"I take the view that a mark of a politician is not made when times are good but when you are faced with challenges.
"I intend to face this challenge and to deal with the issues in front of me and to bring about cost reduction for the scheme."
The Renewable Heat Incentive (RHI) paid out more than the fuel cost, meaning users could earn more the more they burned, leading to claims of an "ash for cash" scam of heating buildings unnecessarily.
For a spell Mrs Foster was in charge as the North's Enterprise, Trade and Investment Minister.
Mrs Foster said officials are to write to those who receive payments asking if their names can be disclosed, as required under data protection rules.
"What is important for us is that we bring forward proposals to the Assembly in early January to make sure that we reduce the potential cost of the scheme to make sure that it does not cost the sort of money that has been talked about."
Mrs Foster said a whistleblower sent correspondence to her which she passed to officials to deal with. "That is the accepted way that you deal with these issues.
"If someone comes to you about a matter concerning the department you then give it to officials to deal with and that is exactly what I did.
"I regret of course that it was not dealt with within the appropriate fashion."
She said normally such issues were brought back to the minister after being dealt with and they did not happen in this case.
"I do regret that that is the case."
She said most of those who benefited were legitimate businesses which applied into a scheme which had a good policy aim - to cut carbon emissions.
"It is entirely wrong to smear all of those people in a way that some (news) outlets have been trying to do."
She said Northern Ireland needed its own scheme because more people in the North were moving from oil to renewables than in the UK, where gas predominates.
"Unfortunately they got it wrong and the design of the scheme was wrong."
She said the advice given to her by senior officials did not reflect adequate checks and balances.
"None of the alarm bells were ringing before I left the Department because at that time we had an underspend in relation to the RHI and it was only later that the overspend was projected and that is when alarm bells started to ring.
"If they had listened to the whistleblower at that particular time then we would have been able to deal with the issue at an earlier stage."
She said there was no bar on members of the DUP or anyone else applying to the scheme.
"Most people who applied into the scheme did so in a legitimate fashion. We want to find those people who set out to abuse the scheme, that is the key for me and for the Department."