Business leaders today raised fears that the Government is poised to scrap major plans for the upgrading of the road between Londonderry and Belfast via Dungiven.
Ian Crowe, president of the city's Chamber of Commerce, today issued an urgent rallying cry to politicians and community leaders to "stand together with business" against any claw back.
Former Secretary of State Peter Hain announced the £250m funding for the dual carriageway between the Derry and Dungiven stretch of the project in December 2005.
The A6 dualling project was to be the largest project of its kind in Northern Ireland when it was announced and would cut journey times between the first and second city, running via Toome and Castledawson.
Mr Crowe said today, however: "The scheme was included in the Strategic Investment Board's first investment strategy but has mysteriously disappeared from the NI Assembly's plans for Northern Ireland from now up to 2018.
"In response to our requests for clarification on the timeline of the scheme, we are told that it might be put back, or be on hold and it has even been hinted that the North West's link to the capital city will be via Strabane, Omagh and Dungannon once the A5 is upgraded using the Republic's money."
Janice Tracey, chamber chief executive, added: "We need to do something very, very quickly to point out that this would be totally unacceptable and has the potential of setting back the current regeneration of the city.
"I would urge our MPs, MLAs, councillors and community representatives in the entire region to take urgent action immediately to lobby to have this scheme put back into the Programme for Government."
Foyle SDLP MP Mark Durkan today said: "I share the concerns over the confusion surrounding the commitment to the upgrading of the A6.
"In recent months we have heard different statements. We need clarification on all of this.
"An investment strategy for Northern Ireland that isn't clear and real about the Derry to Belfast road would not be a strategy worthy of the name or of devolution."
The Chamber of Commerce and Derry City Council, on behalf of the Civic Regeneration Forum, have now written to Regional Development Minister Conor Murphy asking for an urgent meeting to discuss the "critical" issue.
Responses to the Programme for Government are due in by January 4 with the Assembly expected to agree the programme shortly afterwards.
Mr Crowe said that given the time-frame "everyone needs to weigh in behind this cause and our colleagues in Belfast need to realise that the road goes both ways".
No one was immediately available for comment at the DRD.