The scandal led to the collapse of the Stormont executive nearly a year and a half ago
Arlene Foster is due to answer questions about her role in Northern Ireland’s botched Renewable Heat Incentive Scheme today.
The DUP handling of the so-called ‘Cash for Ash’ scandal led to the collapse of the power-sharing executive at Stormont in January 2017.
The late Martin McGuinness resigned his position as Deputy First Minister over Mrs Foster’s refusal to stand aside from her position while the inquiry into the scheme was ongoing.
A string of attempts to bring an end to the political impasse and restore the assembly in the months since have come to nothing.
Sinn Fein's Vice President Michelle O'Neill has confirmed new talks will start next week - aimed at restoring the executive.
“We will be there,” she said.
“We will be talking next week – as we have done throughout the last year and a half, trying to talk to al the key people we need to be talking to.
“Particularly the Tánaiste and the British Government who have allowed a vacuum since the talks collapsed back in February.”
The scandal revolves around the Renewable Heating Incentive (RHI) scheme which was designed to encourage businesses to replace older heating sources with more eco-friendly alternatives.
Errors in the legislation meant that the subsidies exceeded the cost price of the fuel - with businesses paid around £1.60 for every £1 of fuel purchased through the scheme.
As a result of the errors, the more fuel users burned, the more money they could claim - leaving the scheme drastically oversubscribed.
The scheme was drastically oversubscribed, leading to fears it could end up costing the North £500m (€573m).
Arlene Foster oversaw the establishment of the scheme during her time as the North’s enterprise minister.
The controversy also led to division within the DUP after party member Jonathan Bell gave an interview to the BBC in which he said Mrs Foster was "hostile," "abusive" and "highly agitated" when she "overruled" his attempt to close down the scheme early.
He said two senior DUP advisors had “intervened” to prevent the closure of the scheme and secretly tried to “cleanse the record” of Mrs Foster’s involvement.
The DUP leader has insisted she has done nothing wrong.
Yesterday, in a witness statement, she said she couldn't recall being warned of the dangers of there being no cost controls for the scheme.