The bypass will now be bundled together with the £100m Balmedie to Tipperty road scheme and let as a single contract.

First minister Alex Salmond said work would start immediately with prior information notices to be issued this week and drilling works to commence on site next month.

The project will go to tender early next year, with works now expected to be completed by spring 2018.

Salmond is keen to push the project through following five years of legal wrangling with protesters.

He said: “The decision by the Supreme Court is a just ruling for the north east of Scotland and an opportunity for Scotland that marks the end of five incredibly frustrating years for the vast majority of people who are behind this ambitious project.

“Over the next three decades, the AWPR and the Balmedie to Tipperty road schemes are expected to bring in an additional £6 billion to the local economy, creating around 14,000 new jobs.

“It is therefore crucial that we crack on and deliver these vital and frankly long overdue infrastructure projects.

“Work will now proceed apace, and I am delighted to announce that a prior information notice signalling the start of procurement for the project will be published in the coming days with investigative drilling set to begin on site next month.

“We anticipate that this long-awaited project will be underway in 2014 and complete by the spring of 2018.

“Quite clearly, these unwanted delays will result in a substantial increase in the overall cost of this project, but its value to the north east and wider Scottish economy is such that it must go ahead.

“Work will now begin to quantify the total project costs and we will update Parliament with revised figures as soon as possible.”

The construction contract will stipulate that all job opportunities must be advertised through local job centres and all subcontracts to be tendered must be advertised on the Public Contracts Scotland web portal.

Timetable for the new combined project

October 2012 – Publish prior information notice.
Early 2013 – Hold industry day to discuss tenders.
Early 2013 – Publish Official Journal of the European Union (OJEU) notice.
Spring 2013 – Issue invitation to tender.
Autumn 2014 – Award contract/commence works.
Spring 2018 – Completion.

Preparatory work has already started along the AWPR route, including archaeological and environmental surveys and Transport Scotland will shortly announce details of future planned advance works.

Ground investigation work for the Balmedie to Tipperty scheme is also well underway, and procurement for a supplementary ground investigation on the AWPR has started and is expected to begin next month.