Scotland’s transport secretary has told parliament he is unable to give a definitive date for the Aberdeen bypass opening.

The £745 million road, officially known as the Aberdeen Western Peripheral Route (AWPR), has been hit with a series of delays due to weather, the collapse of contractor Carillion and technical problems.

The Scottish Government had most recently hoped it would be completed by late autumn but Transport Secretary Michael Matheson told MSPs in a statement at Holyrood the consortium behind the project, Aberdeen Roads Ltd (ARL), is now targeting a December date for the whole road.

He said problems discovered in May at the new Don crossing are more “extensive” than initially believed but repairs will not add extra cost to the public purse.

Mr Matheson added: “However, they were unable to provide a definitive date for the opening of this section as there are number of factors which could influence this date, including technical issues and other physical factors such as the weather.

“We’ll continue to closely with ARL to ensure that everything that can reasonably be done is being done and we will provide a definitive date for the opening of this section as soon as possible.”

The transport secretary said he is “disappointed” at the progress of talks to open a near 20-mile stretch of the road between Craibstone to Stonehaven and Charleston, which requires a variation to the original contract.

He said a letter from one of the ARL contractors Galliford Try on Wednesday cast doubt on this, suggesting ARL has not yet agreed to open this section and said it had not yet been brought up with their lenders.

He said this is despite verbal assurances to the contrary and this “inconsistency” is frustrating efforts to open this part of the road.

“It is time for the contractor to stop deliberating and start acting,” he said.

“It now has to take the necessary steps to open the majority of this road and let the people of the North East enjoy the benefits they have been so patiently anticipating.”

Conservative Liam Kerr questioned if the Scottish Government has “lost its grip on the process” and said management of it has been a “disgrace” as it was originally due to open last winter.

He added: “Today’s statement lists various structural, contractual and communication problems that make clear that (Mr Matheson’s) latest teaser that it might be December is never going to happen.”

Labour’s Colin Smyth said: “It’s just not good enough that the Transport Secretary today cannot give parliament today a firm date when this project will open.”

He questioned the final cost of the road, which Mr Matheson did not provide.