Transport Secretary Michael Matheson says the Covid-19 pandemic has impacted on dualling the A9 but failed to give any definitive timescales.
The £3 billion project to dual the route between Perth and Inverness, which was first announced a decade ago, had a target completion date of 2025.
But this appears to have slipped as a result of the pandemic, with First Minister Nicola Sturgeon admitting last year the timescales were “ambitious”.
Scottish Conservative MSP Murdo Fraser raised the issue at Holyrood, asking for an update on when the project is expected to be completed.
The MSP for Mid-Scotland and Fife said he is “concerned we still do not have any definitive timescales for completion of the work”.
He added that homeowners along the A9 route “don’t know whether their properties will require to be compulsory purchased or not”.
In response, the transport secretary admitted Covid-19 has impacted the project but would not give any indications on how far timescales had slipped.
He told MSPs a procurement exercise is ongoing for the project, which is due to “complete in the coming weeks”.
This should put ministers in a “better position to inform what the final delivery timescale will be for the completion of the road”, Mr Matheson added.
The SNP minister said design work for the remaining eight sections is “well advanced”.
Speaking afterwards, Mr Fraser said: “I was disappointed to hear the cabinet secretary yet again fail to provide any clarity on when the A9 dualling will be completed.
“We were initially told it would be done by 2025 but that obviously won’t happen now.
“I acknowledge that the pandemic got in the way but all we heard from the Cabinet Secretary today was a lot of talk about procurement and how the SNP Government would need to wait until this procedure was finalised until they could give an approximate date of completion.
We were initially told it would be done by 2025 but that obviously won’t happen now.
“That isn’t good enough and I find it very frustrating. I am concerned that we still have no clarity on a completion date given the amount of interest there is on the A9, with it being one of Scotland’s most dangerous roads.”
The A9 dualling programme, one of Scotland’s biggest infrastructure projects, will upgrade 80 miles of road from single to dual carriageway to better connect Perth to Inverness.
Two out of 11 sections have been completed so far, between Luncarty to Pass of Birnam, and from Kincraig to Dalraddy.
Preparation works for the stretch between Tomatin and Moy in the Highlands began last month and are due to be completed by summer 2022.