A plan to cut the overspend of Stormont's botched green energy scheme was the idea of a political party special adviser (SpAd) not a civil servant, an Assembly committee has been told.
Dr Andrew McCormick, the senior civil servant at the Department of Economy, did not name the SpAd but made clear it was not the adviser working within his department, Democratic Unionist John Robinson.
In response to the revelation to the Economy committee, Alliance member Stephen Farry raised concern the plan was a "political fix" to overcome the "hurdle of an election" or to "take the heat off a media furore".
Dr McCormick insisted there was "nothing untoward" about a special adviser feeding ideas into internal departmental decision-making processes.
Giving evidence to the committee, Dr McCormick said the one-year plan would not provide compensation for applicants to the lucrative state-subsidy scheme. He said such issues would be examined by an anticipated longer-term plan.
The departmental permanent secretary also apologised for the non-appearance of DUP minister Simon Hamilton, who had been invited to brief members on the initiative to reduce the projected £490 million overspend.
While Dr McCormick again acknowledged the civil service's failure not to spot the errors, he also asked why no one from within the renewable energy sector, apart from a lone whistleblower, flagged the issues to government.
The role of DUP SpAds has been the source of controversy throughout the Renewable Heat Incentive (RHI) scandal.
One of them - Dr Andrew Crawford - resigned last week over allegations, which he denies, that he exerted influence to keep the RHI running at high tariff levels.
Meanwhile, Mr Robinson stood aside from any role in the RHI, to avoid a conflict of interest perception, after the media revealed that his father-in-law ran two of the green boilers.
Dr McCormick was briefing Economy committee members on Mr Hamilton's 12-month plan to clamp down on the projected overspend.
It involves moving applicants who had signed up to high tariff returns onto a reformed payment scale for 12 months and also launching a consultation for a longer term fix.
The plan is likely to face legal challenge from applicants to RHI who signed up to 20-year contracts.
The RHI scandal triggered the collapse of powersharing in Northern Ireland and the calling of a snap election after Sinn Fein's Martin McGuinness quit as deputy first minister in protest at the DUP's handling of the affair.
Dr McCormick's revelation that a SpAd came up with the plan prompted concerns from some committee members.
Mr Farry said: "Whenever I hear that the instigation of this particular mitigation came at a political level through a special adviser, that in some ways makes it more difficult for me to believe this is a genuine bottom-up civil service approach as opposed to political fix to get us over the hurdle of an election or to take the heat off us in the context of a media furore."
DUP committee member Mervyn Storey accused Mr Farry of politicking.
"You are just making political points," he said.
Dr McCormick stressed that there was nothing unusual in special advisers feeding in their ideas.
"It's normal practice," he said.
"There's nothing untoward or strange about where the idea came from."
Mr Farry also branded Mr Hamilton's decision not to face committee questions a "disgrace".
Committee deputy chair Steve Aiken said he should have attended.
"He should have been here," he told Dr McCormick.
The permanent secretary replied: "Apologies on behalf of the minister."
Mr Aiken told Dr McCormick: "You don't have to apologise I hope he would apologise himself going forward."
A spokeswoman for the minister later said: "The minister had been invited to the Economy committee however he had not confirmed his attendance."
Much of the committee discussions focused on the threat of Mr Hamilton's plans being the subject of a judicial review by disgruntled RHI applicants.
Mr Aiken said a successful legal challenge should force the minister from public office.
He said: "Now that the risks lies with the minister and we are going to be in a situation where we are likely to face significant legal challenge - and if this legal challenge is successful I would look to the minster to forthwith resign from any public office because there is a considerable degree of concern across Northern Ireland on these issues."
Dr McCormick suggested the fact applicants ended up obtaining a rate of return better than the one they were told they might expect should not necessarily mean they should be compensated.
He said any concerns that the overspend fix plan was "unfair" would be addressed when it came to establishing a long-term plan for 2018 onward.
The high-ranking civil servant said the courts would also likely take in to account the relatively few number of whistleblowers who came forward to flag up the problems with the boiler scheme.
"Shame on us for not having spotted the problem until too late," he said.
"But there is also a significant issue as to why people continued to burn and nobody told us.
"That should affect how it is assessed by the court."
