MLA Jim Wells has claimed the DUP put pressure him not to force a public vote on gay conversion therapy and there was a "mass rebellion" among its Assembly members on the issue.
Mr Wells, who has had the DUP whip removed but remains a party member, made the comments on the BBC Stephen Nolan programme.
Last week the Assembly passed a UUP motion calling on the communities minister to ban gay conversion therapy in Northern Ireland.
A defeated DUP amendment had supported banning the practice, but sought protections for “legitimate religious activities such as preaching, prayer and pastoral support” with the argument they did not amount to conversion therapy.
The amendment also faced criticism from political rivals for removing the line from the original motion stating that it was wrong to view the LGBTQ community as requiring a "fix or cure".
Mr Wells claimed the DUP leadership had wanted all its MLAs to abstain on the motion.
He said there was “a mass rebellion” at a DUP Assembly group meeting where the bulk of the membership (23 members) made it clear there was no way they would abstain.
Mr Wells said the party had then hoped the motion would slip through without a vote, and that the five party members intending to abstain would not be recorded, including party leader Arlene Foster.
After texting all DUP MLAs to let them know he would be pressing the issue, Mr Wells said he was politely asked by a leading DUP member to “drop it”.
“I made it absolutely clear to him that ‘no, I was pushing it to a vote’,” he said.
“And I can see why he asked for that, because that showed that the party leader and shockingly (Economy Minister) Diane Dodds...that is the real shock here ... had decided to abstain on the vote.”
It has been reported DUP leader Arlene Foster is attempting to soften the party’s stance on the issue.
Mr Wells said it was clear that Mrs Foster and Mrs Dodds were trying to push the party in a direction it didn’t want to go.
He said the potential outcome would have been to put religious leaders in prison after praying for someone struggling with same-sex attraction.
A DUP spokesman said: “We support a ban on conversion therapy but the original motion took no consideration of religious freedom. We could not support the motion after our amendment was defeated. It was a matter for members whether they abstained or voted against. There was no whip applied.
"We will not support, indeed we will veto, any legislation which does not contain robust protections for churches. The party leader met with representatives of the faith sector on Wednesday. We will work constructively with all parties to ensure that harmful practices are banned but religious freedom is not curtailed,” he said.