The widow of DUP founder Ian Paisley has blamed the party for the powersharing impasse at Stormont.
Baroness Paisley said it should accept responsibility for the botched green energy scheme which led to the collapse of the devolved institutions 13 months ago.
She told BBC Radio Foyle: "If you are a minister and someone in your department is wrong, the buck stops at your desk.
"You have got to do what is right and stand down from your position until the matter is sorted out.
"If that had been done at the beginning, there would have been a very different situation than the one we are in at the minute.
"We would not be in the mess we are in."
DUP leader Arlene Foster was the minister in charge of the Stormont department which ran the overspending Renewable Heat Incentive (RHI) scheme.
Mrs Foster refused to stand aside while an investigation was carried out.
She has not been accused of any wrongdoing but the role played by DUP ministerial advisers has come under scrutiny.
Former Sinn Fein deputy first minister Martin McGuinness resigned in protest at the DUP's handling of the scheme, which paid generous subsidies to businesses using wood fuel and earned the moniker "cash for ash".
The resignation promoted the folding of the devolved institutions, and endless talks between the parties and British and Irish Governments have failed to resurrect them.
Mr Paisley led the administration at Stormont along with Mr McGuinness.
He died in 2014.