The DUP's surprise defeat in a local government by-election in Co Down is "a massive wake-up call for the party", senior sources have told the Sunday Tribune.
Prominent figures believe there must now be "personnel changes" at the top and are prepared to urge the Rev Ian Paisley to make a declaration of intent to step down as leader, party insiders said.
Such a declaration should be made by the autumn at the latest, they said. Paisley will be told this is in the interests of the party. However, the DUP leader, who will be 82 in April, is known for making up his own mind.
He has previously announced he has no intention of resigning as First Minister or party leader, and his likely response to such requests is unknown.
The DUP, clear favourite to take the Dromore seat, saw its vote decline dramatically following a new hardline challenge. It polled 29% compared to 20% for Jim Allister's Traditional Unionist Voice (TUV) formed only two months ago.
Allister, an MEP, resigned from the DUP over entering government with Sinn Féin. The Ulster Unionist Party, which has been in the electoral doldrums for years, won the seat on TUV transfers. Senior DUP figures believe their leader's friendly relationship with Martin McGuinness, which has led to the pair being dubbed 'the chuckle brothers' is disastrous for the party.
They also claimed a stream of stories about Ian Paisley jnr's relationship with North Antrim property developer Seymour Sweeney had been equally damaging. Senior DUP figures are now questioning how long Paisley jnr can survive as a junior minister at Stormont.
Sources said the DUP appeared far too cosy with Sinn Féin and must adopt a "more business-like approach" to the party. "We need a sharp, competent team, punching at its weight," one said.
Another stated: "It's not just the Doc. There are too many smiles on too many bakes among our people at Stormont. We appear smug and pleased to be in power. We look joined at the hip to Sinn Féin. Greater detachment is needed."
The party should demand more loudly that the IRA Army Council is disbanded and should be lobbying for a date to end the requirement for mandatory coalition government at Stormont, DUP sources said.
Some also said their party should be exerting pressure for an Orange Order march along the Garvaghy Road in Portadown. Dromore wasn't natural terrain for the hardline TUV which could be expected to perform even better in constituencies like Upper Bann and East Antrim.