A former DUP minister who broke ranks to accuse party figures of wrongdoing over Stormont’s botched green energy scheme has been demonised for telling the truth, his lawyer has claimed.

Jonathan Bell’s decision to go public with explosive claims against party leader Arlene Foster and a number of DUP ministerial advisers has come at “enormous personal and professional expense”, the inquiry into the Renewal Heat Incentive (RHI) was told.

Giving a closing submission to the inquiry, Mr Bell’s lawyer Ronan Lavery insisted the former energy minister never had a vested interest in the ill-fated initiative, and instead had only been guided by the public interest.

On the penultimate day of hearings at Stormont, Mr Lavery said if Mr Bell had not spoken out, the RHI the inquiry might never have happened.

Renewable Heat Incentive schemeDUP leader Arlene Foster

“He has been the subject of personal attacks and smears and they have sought really to discredit him personally, rather than anybody in any way effectively undermining the truth of what he is saying,” he said.

“He has been accused of violence, drunkenness, incompetence and even, and this is from the press office, a ‘monster that had to be put to sleep’. And Arlene Foster in the course of her evidence suggested that he might even be responsible for the collapse of government in Northern Ireland.”

The inquiry is examining the fatal flaws in the development and operation of a scheme that landed Stormont with an overspend bill once projected at almost £500 million.

The RHI was supposed to incentivise farmers and other business owners to switch to wood pellet burning boilers by offering them a subsidy to purchase the fuel.

Catastrophic errors meant subsidy levels were set higher than it actually cost to buy the pellets, so applicants were effectively able to make a profit on public money by burning boilers without limits.

Mr Bell was the energy minister at Stormont in the final months of the scheme and was in charge in the period when cost controls were finally introduced and, later, when it was ultimately closed down to new applicants.

RHI public inquiryEco-friendly wood chip boilers similar to the batches used as an incentive in Stormont’s botched green energy scheme.

He broke ranks in December 2016 and went public with a series of allegations, the foremost being that senior DUP advisers conspired to thwart his efforts to control the spiralling costs of the RHI.

He alleged some within the DUP wanted to keep the scheme running due to vested interests and associations with people who were directly benefiting from it.

Mr Bell’s high-profile claims contributed to the political maelstrom that weeks later saw powersharing in Northern Ireland collapse, when Sinn Fein pulled down the institutions in protest at the DUP’s handling of the affair.

Subsequent to him going public, and during the course of the inquiry, DUP figures have made a series of counter claims against Mr Bell.

They included allegations of aggressive and intimidatory behaviour; of being thrown out of a New York bar for being too drunk; of threatening to break his own special adviser’s finger and of general poor performance in ministerial roles.

On Thursday, Mr Lavery told inquiry chair and retired judge Sir Patrick Coghlin: “It is Mr Bell’s submission that without the disclosures which he made that this inquiry probably would not have been held and it’s been at enormous personal and professional expense to Mr Bell.”

Mr Bell is no longer a DUP member and has returned to his former profession of social work.

Mr Lavery told the inquiry panel his decision to go public was motivated by a desire to control the RHI costs and ensure that mis-governance inherent in the scheme was not repeated.

“His commitment has been to act justly,” he said.

“He has not had a vested interest in this scheme or anything involved here, he didn’t have family members who owned boilers – the only thing guiding him was the public interest.

“He has been disparaged and demonised.”

Mr Lavery claimed that the only individuals who have criticised Mr Bell during the inquiry were DUP figures.

During the inquiry it emerged that Mr Bell had secretly recorded a number of conversations he had during the RHI controversy, including with former DUP first minister Peter Robinson and a senior Stormont civil servant.

His lawyer said Mr Bell acknowledged that he should not have made such recordings, but he said the ex-minister was only attempting to “safeguard the truth”.

A lawyer for Mr Bell’s former special adviser in the energy department – Timothy Cairns – also made a final submission on Thursday.

Rows and discord that characterised the men’s working relationship have been laid bare during the inquiry.

Richard Smyth, acting for Mr Cairns, said he had regrets about aspects of his time with Mr Bell but was confident he had acted appropriately in his handling of the RHI.

“The chronology shows that Mr Cairns in fact acted reasonably and appropriately and did not breach relevant codes pertaining to his role at that time,” he said.

“That is not to say, members of the panel, that things could not have been done differently with hindsight.”