A former DUP politician who quit to join the Ulster Unionists has written to former colleagues urging them to speak out on the RHI scandal.
Jenny Palmer left the DUP after accusing it of failing to address her allegation she was pressurised by a party special adviser in relation to a furore around social housing contracts.
The former DUP councillor joined the UUP and was elected as an MLA for Lagan Valley in last year's election.
Her appeal to DUP members comes after current party figures Jonathan Bell and David McIlveen both publicly criticised their leader Arlene Foster for her handling of the Renewable Heat Incentive (RHI) affair.
In an open letter, Ms Palmer told her "good, honest friends" within the DUP they did not have to put up with scandals.
"I used to get people telling me that while they valued the contribution I made to public life, they were horrified by the behaviour of the upper echelons of the DUP," she wrote.
"If you stay silent, you give your implicit consent for the people responsible to get away with this.
"You alone at this moment have the power to say to those people 'no'. The voters will have their chance in a few years, if not sooner, but at this moment in time, almost no pressure from opposition or the media will have the same impact as you standing up and saying to the party 'no more'.
"I know, because I did it. I know what power even a councillor can have by just publicly saying 'this is wrong'.
"I understand your reluctance. I know how terrifying it is to go against the juggernaut of the party apparatus. That deep, sleep-preventing fear of 'what if I do it'. That fear that you'll lose friends, you'll lose income, you might even lose your career. I know, because I went through it.
"I won't lie to you, it might happen. I lost friends. I lost income. It didn't end my career, because I have the backing of the voters and my new party, but there were no guarantees.
"But I had to do it, even if my crusade was a lonely one. It was the right thing to do then, and you know that it is the right thing to do now."
In conclusion, she wrote: "I want to close with a few words the late Dr Paisley shared with me when I was going through my own purgatory. He said, 'keep the faith, Jenny'.
"If you know that what is happening is wrong, speak up. If they dare to try to attack you for speaking the truth, I believe that you will be rewarded as I have been.
"With love, Jenny."
