A new poll has seen support for the DUP slump to 13%, being overtaken by both the Ulster Unionists and the TUV.
The LucidTalk poll for the Belfast Telegraph saw DUP support drop by three points, making it Northern Ireland's fourth most popular party, tied with Alliance and the SDLP.
Sinn Féin has held firm as the most popular party on 25%, followed by the UUP on 16%, up two points.
It is the first time in more than 20 years that the UUP has been Unionism's leading party.
Jim Allister's Traditional Unionist Voice saw big gains, rising by 3% to make it the third most popular party on 14%.
But the decline of the DUP continues, with the party dropping three points to 13% since the last poll was taken in May, at a time of chaos in the party when Edwin Poots replaced Arlene Foster.
It will make worrying reading for Jeffrey Donaldson, who replaced Mr Poots as leader when he stood down after 21 days in the role.
The poll suggests that DUP support has more than halved in three years, having stood at 31% at the 2019 Westminster election.
After making steady gains in recent polls, support for the Alliance Party has dropped 3% to 13%, having been tied as the second most popular party with the DUP in May.
Support for the Green Party is on 2%, People Before Profit is also on 2%, and another 2% opted for "others".
The results could leave Sinn Féin vice president Michelle O'Neill on course to become First Minister after the next Assembly elections due to be held in May 2022.
Doug Beattie of the UUP would then become Deputy First Minister, the poll suggests.
Meanwhile, health minister and UUP member Robin Swann has been voted the most popular leader in Northern Ireland, with 75% rating his performance as good or great.
UUP leader Mr Beattie was next, with 44% rating his performance as good or great, followed by Alliance leader Naomi Long on 38% and SDLP leader Colum Eastwood on 24%.
Despite unprecedented gains for his party, TUV leader Mr Allister was the least popular, with 51% rating his performance as bad or awful.
He was followed by First Minister Paul Givan, with 48% rating him as bad or awful, Mr Donaldson was on 47% and Ms O'Neill was on 45%.
Meanwhile British Prime Minister Boris Johnson and Northern Ireland Secretary Brandon Lewis both remain very unpopular, with 79% and 77% respectively rating their performances as bad or awful.