Business leaders in Scotland's largest city have demanded that work on the �500m M74 extension starts immediately. Glasgow Chamber of Commerce told the Scottish Executive that work on the completion of the M74 must start "as quickly as possible".
The news came as Finance Minister John Swinney gave his plans on major transport projects across the country.
The M74 is scheduled to start construction in 2008, with the project due for completion in 2011.
Glasgow Chamber's chief executive Dr Lesley Sawers said: "The business case for the completion of the M74 has been made and accepted.
"The contract has been put out to tender and the market has responded, with a consortium submitting a fully costed proposal.
"This project should not be revisited for the sake of political expediency, it will only create further delays and may actually lead to an increase in cost.
"There have been enough delays on this project and we strongly urge the executive to get it underway as quickly as possible with the necessary protections in place for the public purse."
Glasgow City Council leader Steven Purcell has said the extension would bring economic and social benefits to the entire west of Scotland.
Last year, Friends of the Earth (FoE) Scotland and Joint Action Against the M74 (Jam74) ended their action to block the project on legal advice.
The groups had been appealing against a decision by the Scottish Executive to press ahead with the scheme.