Sinn Fein and DUP ministers were at loggerheads over tackling RHI crisis
Simon Hamilton has said that distrust was "probably mutual" with Mairtin O Muilleoir when the two ministers were trying to find a solution to the RHI crisis.
In witness statements released last night, the former DUP economy minister accuses the then Sinn Fein Finance Minister of interfering in his brief.
But Mr O Muilleoir states he was "baffled and frustrated" by Mr Hamilton's "failure to bring forward proposals promptly" to bring the scheme under control.
He claims that he and his officials "repeatedly urged" the DUP minister to "resolve RHI" and that he was "willing to give Minister Hamilton the benefit of the doubt".
The Sinn Fein MLA adds: "Although I could not compel Minister Hamilton to resolve RHI, my officials and I repeatedly urged him to do so."
Between June 7, 2016 and January 5, 2017, Mr O Muilleoir says he took steps to address the issue, including meeting with Simon Hamilton six times to discuss RHI.
Officials from DfE and the DoF were also in contact over the scheme.
However, Mr O Muilleoir said that, due to a lack of proposals on how to solve the crisis and "with a series of disturbing revelations on the DUP's involvement in the scheme", he "came to the conclusion that Minister Hamilton was not co-operating with me to find a solution".
He said that he viewed a media announcement on January 4, 2017, which Simon Hamilton had agreed with Arlene Foster without referencing him, "as evidence that Minister Hamilton did not intend to include me in developing a solution".
He added: "The approach adopted by Minister Hamilton hindered the development of a solution to RHI."
Mr O Muilleoir, who approved the business case for the RHI regulations on January 25, 2017, said that neither he nor anyone acting on his behalf briefed the media criticising Simon Hamilton, and that he "sought at all times to be supportive and respectful towards Minister Hamilton".
However, he said he did not believe the 2017 regulations introduced to curb the scheme's spending were "the best way to mitigate the expense".
Mr O Muilleoir said that Sinn Fein's view of RHI was that it is a "fundamentally flawed scheme which is not effective in its original aim of reducing carbon emissions".
Meanwhile, in his witness statement, Mr Hamilton expressed "concern" about Mr O Muilleoir's "style of doing business".
He added: "Given that I was a DUP minister and he was a Sinn Fein one, distrust was maybe unsurprising and probably mutual.
"I noticed that Mr O Muilleoir had a tendency to engage with bodies that were accountable to me as DfE minister without prior discussion with me and involve himself in issues in a way that I believed to be interfering and stepping beyond his brief."
Following the airing of the Spotlight programme and the Nolan interviews in December 2016, Mr Hamilton said that the "relationship with Sinn Fein deteriorated generally".
He stated: "An already uneasy working relationship was not helped by the fact that I found my interaction with Sinn Fein becoming hallmarked by suspected media leaking and briefing by them, a belief that they were seeking a political advantage from the whole issue of finding a solution to the RHI problem, an ongoing attempt by Sinn Fein to unfairly characterise the Democratic Unionist Party as being uninterested in finding a solution because of unfounded allegations of corruption, and casting themselves as the saviours of the situation".
Mr Hamilton rejected a claim that he had leaked any solution options, and said he believed his spad had not done so either.
He added: "It was also evident to me during this period that Sinn Fein were actively seeking to gain a political advantage from the issue of the cost control proposals presumably with the dual intention of inflicting political damage on the DUP and to portray themselves as the only party interested in solving the problem."
Meanwhile, Mr O Muilleoir said he "did not take any action to promote" the botched green energy RHI scheme, and was "speaking only for myself" in an email in which he vowed that the "utmost" would be done to have as many RHI projects as possible green-lit before the scheme's closure.
Mr O Muilleoir told TVI Community Development manager Aisling Brady: "We are assessing our options at the minute and will do our utmost to have as many projects as possible green-lighted."
As to the "we" in the email, he said that he was "speaking only for myself".
He added that he "had no specific options in mind" and "pursued no other options".
Mr O Muilleoir said his email to Ms Brady reflected the fact that he was "sympathetic to the plight of those who would be adversely affected by the closure of the scheme".
He stated: "By 'green-lighted' I meant 'accredited'."
He also insisted that he "had no involvement" in delaying the closure of the scheme, and knows of "no connections to scheme beneficiaries".
In his evidence, Mr O Muilleoir said that he had been informed in an email by Sinn Fein MLA Conor Murphy on February 10 that the closure of the botched scheme was being delayed until February 29, 2016.
Mr O'Muilleoir said he "supported" the decision to delay the scheme's closure to allow "businesses, social enterprises and community groups who had paid for equipment in good faith to complete accreditation."
He continued: "I was aware of a concern that immediate closure of the scheme could result in a legal challenge which, if successful, could lead to the scheme remaining open indefinitely.
"I was also aware of concerns that immediate closure could result in job losses.
"I considered that this short delay gave the best opportunity to close the scheme at the earliest opportunity without inviting a legal challenge which, had it occurred, could have defeated any decision to close the scheme at an earlier time."
When asked if he or any other Sinn Fein representatives, spads or staff had taken action to help projects be "green-lighted before the suspension or closure of RHI", he replied: "No actions were taken."
When asked what role Conor Murphy or any other Sinn Fein representative, spad or staff member played in securing the two-week extension to RHI, Mr O Muilleoir claimed he did "not know the details of how the closing date was agreed".
"To the best of my belief, I believe that they would have advocated for a sustainable decision to close the scheme at the earliest possible opportunity," he said.
Mr O Muilleoir said he "played no role" in securing the extension "other than to support the decision".
He further stated that he "cannot recall any discussion" over whether Sinn Fein should support the delay in the Assembly, adding that MLAs were probably informed of the party's position by the party's whip.
Mr O Muilleoir said he "didn't believe" that Conor Murphy was the person who persuaded Jonathan Bell to delay the closure of the scheme until February 29, 2016.
When asked about the Sinn Fein position as of mid-February 2016, Mr O Muilleoir said it was "that the scheme should be closed as soon as possible".
The evidence also revealed that Simon Hamilton had declined an offer of a Christmas turkey from poultry company Moy Park as he "thought this to be inappropriate in the circumstances".
During a visit to Moy Park's Dungannon headquarters on November 30, 2016, Mr Hamilton said he was "aghast" that the company raised the issue of RHI "where they were effectively looking for more public money to be spent on a new RHI scheme".
He added: "I thought at the time that this showed a great insensitivity to the fact that I was the minister responsible for bringing forward a solution to the significant overspend created by the non-domestic RHI scheme and it also appeared that they'd given no consideration to this factor or where money might come for a new scheme."