Image caption First Minister Arlene Foster said she would not step aside because she had done nothing wrong

First Minister Arlene Foster has again said she will not stand down over the controversial Renewable Heat Incentive (RHI) scheme and said calls for her to do so were "misogynistic".

Mrs Foster set up the scheme in 2012 when she was minister for enterprise, trade and investment.

It was an attempt by the Northern Ireland Executive to help to increase consumption of heat from renewable sources.

RHI is approximately £490m over budget.

The DUP leader has turned down offers of an interview with BBC News NI, but told Sky News she would not stand aside as she had done nothing wrong.

She claimed some of the calls for her to do so were personal and some were because of her gender.

"There's a lot of it personal. There's a lot of it, sadly, misogynistic as well, because I'm a female, the first female leader of Northern Ireland," she said.

"I'm here because the electorate put me into this position. I take the responsibility very, very seriously and I intend to see it through."

Analysis: BBC News NI Political Correspondent Gareth Gordon

Arlene Foster and the DUP have come out fighting in characteristic form.

I think some people will find the misogyny line hard to take.

Among those, as late as yesterday, calling for her to go, is the Alliance leader Naomi Long.

And it's not just Sinn Féin who have been calling for her to go, with virtually every other party in the assembly [also doing so].

But I suppose it suits the DUP to make this, if there is going to be an election, which there could be, as a battle between them and republicans - that this is a strong unionist leader standing up to republicans.

Speaking on Sky News, Mrs Foster accused Sinn Féin of being on a "party political mission" to get her to stand aside in order to weaken unionism.

"Just because I'm a woman, it doesn't mean I'm going to roll over to Sinn Féin. I'm not going to roll over to Sinn Féin. I'm not going to roll over to my political opponents," she said.

Image copyright tchara Image caption The Renewable Heat Incentive scheme is approximately £490m over budget

"I'm going to deal with the issues in front of me because that's what the electorate want me to do."

'Quite nasty criticism'

Economy Minister Simon Hamilton backed his party leader: "If you go and do even the simplest of searches online and social media you will find some quite venomous, some quite nasty criticism of Arlene personally - abusive of her personally - much of which is gender based.

"The criticism being stoked by some within the media and other political parties for their particular reasons is then fuelling that abuse."

Mr Hamilton said over the holiday period he and Mrs Foster had been "working on our preferred option for cost control, that is an option that will come at no cost to the Northern Ireland budget and will keep the scheme running as originally intended".

"We need to take some further legal advice around that, but that's the plan that we're working on, a plan that will reduce that liability to effectively zero."

She said that the terms for an independent inquiry were worked out in consultation with the attorney general and sent to Sinn Féin who, so far, had not responded.

But on Wednesday, Sinn Féin MLA Conor Murphy said they were "insufficient" and that there was no agreement with the DUP on the terms of reference for an investigation.

Last month, Mrs Foster apologised for its lack of cost controls but defended her own role in the scheme.

Businesses were receiving more in subsidies than they were paying for renewable fuel and the scheme became majorly oversubscribed.

'DUP are in denial'

Other politicians have dismissed Mrs Foster's allegations of misogyny.

Sinn Fein's Michelle O'Neill told the BBC Nolan Show: "This is not an Orange and Green issue, or a gender issue. This is about a financial scandal which has the potential to cost the public purse hundreds of millions of pounds".

She also said her party's ministerial team is meeting on Wednesday to discuss the issue.

"The DUP are in denial about the growing public outrage at the misuse of public funds in the RHI scheme and the serious allegations of incompetence, corruption and abuse".

Image copyright Press Eye Image caption Nichola Mallon said calls for Arlene Foster to stand down had nothing to do with her gender

SDLP MLA Nichola Mallon said her party's response to: "... this financial fiasco, the biggest financial scandal to hit this place in the history of devolution would be the same regardless of whether it was a man or a woman at the heart of it all, or whether for that matter it was a unionist or nationalist".

She added: "This has absolutely nothing to do with Arlene Foster being a woman or being a unionist, this is about incompetence, with possible corruption and with unquestionable arrogance from the minister at the heart of it all - Arlene Foster."

TUV leader Jim Allister said that for Mrs Foster to suggest misogyny was behind criticism of her was "beyond belief".

"What lies behind this is great public distaste and unease about the squander of public money, squander made in Stormont, a squander made by Arlene Foster.

"It's nothing to do with gender, it's the fact that she authored the RHI scheme."

Image copyright Press Eye Image caption Alliance leader Naomi Long said the accusations of misogyny were nonsense

Alliance Party leader Naomi Long said it did a great disservice to women in public life "to play the sexism and misogyny card when that is not the issue at stake".

"To suggest that wanting to hold women to the same level of accountability as their male counterparts is in some way sexist or misogynistic is a nonsense," she said

"In fact, to hold them to a lesser standard would be sexism and misogyny."

Ulster Unionist Steve Aiken said it was a "distraction technique" by the DUP.