The Transport Secretary has demanded answers from Aberdeen bypass contractors after yet another deadline was missed.
Aberdeen Roads Limited (ARL) said last month the Don River Crossing, the last part of the AWPR, would be completed by the end of January.
Transport Scotland has confirmed the road will not be opened today, despite all work being complete.
Transport Secretary Michael Matheson said: “Last month, Aberdeen Roads Limited told Parliament the current delays arose as a result of defective workmanship to the Don Crossing.
“In the space of just two weeks following that statement, ARL’s target opening date for the remaining section of the AWPR slipped from before Christmas to January.
“We are now at the end of January and ARL are still not in a position to open this final section. The people of the north-east will want to know why ARL have failed to deliver their own programme once again and I am committed to keeping them fully updated.
“I am pleased to report all remaining physical works at the Don Crossing have finished. But the road can only be fully opened once ministers receive the necessary assurances about the longer term impact of the remedial work and the changed costs of future maintenance.”
He added: “To put it more simply, we are not prepared to pick up the tab for mistakes made by construction companies.
“No responsible government could ever saddle the public purse with uncertain costs for an uncertain period of time.”
North-east MSP Mike Rumbles has said the Scottish Government has “lost its handle” on the bypass project.
He said: “This is just the latest of many occasions where the Scottish Government ministers have decided to let a planned opening date come and go without informing the public.
“From start to finish, the government has done its best to muddy the water around the completion date and the final cost of the road.
“We now know that, after at least six delays to the completion date going back to mid-2017, most of the issues have been caused by poor ministerial oversight, a bungled contract and excessive costs that could total as much as £1 billion.”