First Minister Arlene Foster has supported the need for independent investigation into the RHI scandal but said she will remain as First Minister.
Ms Foster told an a largely vacated Assembly that said she was not immune to the anger the issues surrounding the Renewable Heating Incentive Scheme have caused, and indeed shared it.
She added that the record showed she had always put Northern Ireland first and vowed to continue as First Minister.
“I will continue to work hard, as I have done throughout my political career, to ensure a better and more stable Northern Ireland,” she said.
Earlier Ms Foster said that no-one in government had picked up on the failings within the RHI Scheme.
The DUP leader took to the podium in the Assembly an hour later than expected to address the house after it was recalled to discuss the fall out over the RHI scandal.
Deputy First Minister Martin McGuinness and his Sinn Fein Assembly colleagues walked out of the chamber, along with the SDLP and others, as Ms Foster got to her feet and said that for almost two weeks there has been a “barrage” of media coverage and “hype”, adding that she wanted to “put to rest some of the myths” around the RHI scheme.
“There were shocking errors and failures in the RHI scheme”, she said, adding that these have contributed to the “perfect storm”.
“I am sorry that the initial scheme did not contain cost control measures,” she said.
She said the non-domestic RHI scheme provided payments for 20 years dependant on the heat generated. This was followed by a domestic RHI scheme, which was released in 2014, and Ms Foster said she made “no apology at all” for this extension given what was known at the time.
“However bad the execution has turned out to be, the aims of the scheme were good and necessary,” Ms. Foster said.
“With the greatest of respect to those who criticise me, I would remind them I did not simply impose this on the people of NI,” she said, adding that it was passed by the Assembly. “The unfortunate reality is that no-one in government picked up on this failing,” she said.
Ms Foster said that at no time during her time as Enterprise, Trade and Investment Minister did anyone indicate that cost controls should be implemented.
She also challenged a number of claims made by her DETI successor Jonathan Bell to the BBC Spotlight programme last week, and said a number of documents have now been placed in the Assembly Library.
“The DUP did not ask the DETI Minister to extend this scheme,” she claimed.
“My priority in all of this is not headline grabbing, nor grandstanding, but to ensure lessons are learnt,” she added.
Earlier, Assembly Speaker Robin Newton was repeatedly challenged on his authority to allow separate statements from the joint Executive Office of the First and Deputy First Ministers.
Sinn Fein MLA Carál Ní Chuilín and SDLP MLA Alex Attwood were among those who levelled criticism.
Ms Ní Chuilín said that allowing the speech to go ahead was “challenging the integrity” of the joint office.
Mr. Attwood called for the release of the legal and procedural advice before proceeding.