Mr Bell was given a range of options on closing the RHI scheme and chose the one that would take longest to implement, says Mr Scoffield.

Asked what his approach was and whether he pressed for a quick closure, Mr Bell says that option he went for had been recommended to him by his civil servants on the basis of the legal advice.

Image source, RHI Inquiry

"It wasn't just the legally safer, it was the legally proper way to take this forward."

He wouldn't have overturned the advice he was being given "unless I... genuinely felt I knew better".

"This was what the best expertise in my department was telling me was the soonest available date we could [close the scheme]."

People who leaked information about the impending closure of the RHI scheme in early-2016 were "doing Northern Ireland a gross disservice", says Mr Bell.

"There is no legitimate reason why... you would advertise for more people to come into the scheme."

Image source, PA

DETI officials were told that news of the scheme's closure had got out and that that the poultry production giant Moy Park had instructed its farmers to act quickly and get their applications in.

Then inquiry counsel says the suspicion was that the details were getting out through DUP advisers.

Asked by the barrister if he was aware of any DUP advisers "leaking information that gave you cause for concern", Mr Bell responds: "No."

A submission written for Mr Bell on New Year's Eve 2015 that proposed closure of the RHI scheme was initially sent to the minister's adviser.

He sent it back to DETI officials with a handwritten note suggesting that the Ulster Farmers' Union (UFU) and the renewable heat industry should be consulted on the closure proposals.

Image source, Getty Images

A senior civil servant responded to say that it "would not be appropriate to consult" with the industry given that the scheme had run so far out of control.

Mr Bell claims he doesn't recall seeing his adviser's note and or the original submission.

He says he "gave a very definitive 'no' about consulting the industry" because "it would be counter-intuitive and wrong... to advertise a heads-up to get in before we close it".

DETI's top civil servant was "distressed, very anxious in his tone" during a conversation about the need to close the scheme in early-2016, says Mr Bell.

He says Dr Andrew McCormick (above) told him that the the only way it could be kept open was if Mr Bell issued a ministerial direction, an instruction overruling advice from civil servants.

Mr Bell, who can't remember when the conversation took place, tells the inquiry that he believed that doing that would have been to "break procedures and break law".

"I said to him: 'I'm not prepared to do that... that will not be happening.'"

Mr Bell's adviser told him there would be resistance from within the DUP when plans were being made to shut the RHI scheme at the start of 2016, the former minister claims.

He says Mr Cairns told him that closing the scheme would have a "political impact" and " attract a lot of criticism" for the DUP.

Image source, PA

DUP advisers opposed to the closure for several reasons, he claims, including that it was a good one for the agriculture industry.

Dairy farmers had been having a "very difficult time" and the DUP "wanted to keep the rural economy strong".

In late-December 2015, Mr Bell received a recommendation from DETI officials to close or suspend the scheme and was told a decision was required immediately.

Image source, PA

The Northern Ireland Executive would have to become involved and DETI could expect criticism given the large scale of the unapproved expenditure, he was informed.

The document says that the Treasury had indicated that the cost overrun may need to be covered from the executive's budget.

Inquiry panellist Dame Una O'Brien asks Mr Bell if he's sure that nobody spoke to him before the end of August 2015 about the need to add cost controls to the RHI scheme.

He responds: "I've thought long into the night about this - did people speak to me?

Image source, RHI Inquiry

"I've tried to focus my mind at different times different days - I can't recollect it.

"I'm not saying to the panel that [conversations] didn't happen - I'm saying that I can't recall."

He says there "were literally hundreds of conversations" every day when he was a minister but "I cannot say truthfully if I can recall" if any were related to the RHI scheme.

Applications to the RHI scheme rocketed by 100% in the space of six weeks in autumn 2015 before the overgenerous subsidies were cut.

Mr Bell was given that information in a document from civil servants to prepare him for his appearance in the Northern Ireland Assembly where he would present the cost controls legislation for MLAs to approve.

Asked if he asked "serious questions" about how the spike happened and what could be done to make sure it didn't happen again under his watch, Mr Bell accepts that "maybe I should've pressed" for more information from officials.

He says he understood that the successful applicants had entered into a contract and that there was nothing that could be done to reverse that.

Asked if he should've gone to his adviser Mr Cairns and got him to inform the other DUP advisers about the effect their alleged actions of delaying the cost controls had caused, Mr Bell replies: "Yes, I should have - I didn't do it."

Mr Bell's adviser asked DETI civil servants on behalf of Arlene Foster whether the assembly debate on passing the cost controls for the RHI scheme could be delayed by a week or two.

Tim Cairns posed the question after Mrs Foster had received a query from a constituent in her Fermanagh and South Tyrone constituency.

But a senior civil servant told him that delaying the cost controls by just a week would've added at least £2.6m a year over to the cost of the initiative over its 20-year lifetime.

Image source, Getty Images

Mr Bell says he wasn't aware of the request but he should've been told about it by his adviser.

"Why is my special adviser taking my departmental business and taking instructions... from Mrs Foster?" he asks.

He also wasn't told of the projected cost at the time and he "can't believe... why that didn't come in an urgent submission to the minister".

It causes Mr Bell "great concern" that DETI civil servants didn't tell him that there had been a huge spike in applications to the RHI scheme.

Image source, Getty Images

"Had they told me after week one then I would've looked at urgent procedure... other legislative mechanisms that were in our arsenal to address... that type of concern," he adds.

DETI "seems now to have had that information" but for "whatever reason was not following the agreed process" to bring it to his attention as the minister.

Inquiry counsel Mr Scoffield (below) draws Mr Bell's attention to a submission he received from officials on 6 November seeking approval for the subsidy changes to to RHI scheme be brought to the Northern Ireland Assembly.

The document - marked "urgent" - informs Mr Bell that there had been an "unprecedented surge" in applications and that the projected spend on the scheme has more than doubled.

Image source, RHI Inquiry

Mr Scoffield suggests that the document shows the minister had been informed of the spike and its implications for the budget.

"Why I wasn't told after the first week, the second week, the third week running right up to to the sixth week?" responds Mr Bell.

There was a further two-week delay in getting the regulations for the RHI scheme's cost controls in the autumn of 2015, which allowed more applicants to get signed up, costing the public purse even more money.

Mr Bell says he as no recollection of approving a further delay.

He tells the inquiry that no-one came to alert him about it and he would have directed for it to be addressed urgently if he'd known.

"I understand that during this period if I had any idea that there was a spike in applications - nobody informed me in that through the agreed processes of the department," he says.

"I wasn't aware at all of the spike in applications, nobody was informally briefing."

Mr Bell says he told his department that he would be "retaking" his post during the period of the DUP's in-out ministers policy and instructed it that he'd deal with "all urgent business" in the brief spells when he was in post.

Image source, RHI Inquiry

"I didn't want to be dealing with routine business... but any government business requiring any urgency was to be taken forward," he explains, adding that DETI was working "as normal" even though he wasn't there.

Asked if his ability to drive the officials on was "diluted" in his absence, Mr Bell says he doesn't think so.

The regulations for the changes to the RHI scheme needed to be pushed through the department during October 2015.

But at the time, DUP ministers in the Northern Ireland Executive had adopted a policy of rolling resignations - quitting office before returning for a day or two continually over several weeks.

Arlene Foster (below) remained in post as acting first minister through that time to act as a "gatekeeper" to protect Northern Ireland from "rogue Sinn Féin and renegade SDLP" ministers.

Image source, PA

Mr Bell's adviser Tim Cairns says in his written statement to the inquiry that was part of the reason why the regulations were not ultimately introduced until mid-November.

"The spike in applications wasn't foreseen - if ministers had remained properly and full in post I believe the spike... could've been dealt with by bringing the closure date forward," says Mr Cairns.

But Dr Andrew McCormick, the then permanent secretary at Stormont's Department for Enterprise, Trade and Investment (DETI), which was running the scheme, says in his evidence that he'd spoken to a senior DUP adviser and "came to recognise... that the ministerial resignatons and reappointments had not caused the delay".

He believes it was the result of a delay in drafting the regulations and securing approval for them from Stormont's finance department.

Picking up where the inquiry left off yesterday, matters this morning begin with the agreement at the end of August 2015 to add cost controls to the RHI scheme.

As part of that, it was agreed that changes to the subsidies on offer through the scheme should be pushed back from October that year to November - quite how that came to occur is central to the work of the inquiry.

Image source, Getty Images

Mr Bell formally signed off on the plan on 3 September when officials provided him with a final submission about it.

He says he read the submission and signed it straight away and "didn't ask any further questions about it" at the time.

""I regarded it as a matter that had been resolved," he says.

Mark Simpson
BBC News NI

The RHI Inquiry is not a "media sensational platform", warns the inquiry chairman Sir Patrick Coghlin before he allows the session to start.

Both he and the inquiry QC Mr Scoffield had to intervene at points yesterday when Mr Bell veered into evidence that was deemed irrelevant to the investigation into the hat scheme scandal.

Image source, RHI Inquiry

In his firm tone, Sir Patrick lays down his rules for the inquiry. "It is not a media platform.

"There is no open invitation for witness to come along and use the hearings for the purpose of publishing or referring to material to which they object or take offence for reasons that are irrelevant to the purposes of the inquiry."

Jonathan Bell was a DUP MLA and the minister at Stormont's enterprise department during the period that the RHI scheme did the most damage to the public purse.

Hundreds of millions of pounds were committed when there was a sudden flood of applications in October and November 2015.

But in an explosive interview with the BBC's Stephen Nolan in December the next year, Mr Bell said he tried to close it down before that point, only to be thwarted by DUP advisers.

Image source, Pacemaker

He also accused the advisers of trying to alter documents "without my knowledge, without my consent".

The advisers have denied all of his claims.

He was suspended by his party and stood as an independent candidate in the subsequent Northern Ireland Assembly election in March 2016 but lost his seat, bringing his political career to an end.

Sitting comfortably? Then let's begin...

Image source, RHI Inquiry

Jonathan Bell took the oath yesterday and he's ready for another round of questions from the inquiry's senior counsel David Scoffield QC.

Mr Bell has provided three written witness statements to the inquiry - you can find them here, external, here, external and here, external.

BBC News NI

It is the scandal that sent Northern Ireland's devolved government up in flames and risked leaving taxpayers hundreds of millions of pounds out of pocket.

The RHI debacle has exposed serious flaws in the region's civil service and governance systems.

BBC News NI has followed every minute of the inquiry into the scandal since it started last autumn.

Read our review of some of the major revelations that have emerged so far.