ONLY “bits” of the A1 are likely to be upgraded for now, a Treasury minister has suggested – after the cost of the overall project soared.

Quizzed by The Northern Echo, Chief Secretary Danny Alexander suggested the long hoped-for work between Newcastle and Scotland would take place in “phases” over many years.

And, asked specifically if there would be a dual carriageway all the way, he said only: “I want to go as far as I possibly can on the A1.

“Of course there are constraints, financial constraints, other people’s priorities and so on. It seems to me that this might take a long time to do.”

The comments are the heaviest hint yet that the Government will stop short of dualling the whole of the A1 to Scotland, in a ‘mini-Budget’ on December 3.

The Northern Echo revealed earlier this year that the department for transport (DfT) was exploring two carriageways on an extra 10.5 miles of the route only.

That would leave drivers facing the prospect of frustrating tailbacks on a further 25.5 miles of the A1 to the border, which would remain single carriageway.

Further doubt was cast on the project when the Highways Agency put the bill at anything between £720m and an astonishing £1.2bn.

Nevertheless, David Cameron confirmed this week that some form of A1 upgrade will be part of the “biggest, boldest and most far-reaching” roads programme in a generation, totalling £15bn.

And Chancellor George Osborne will visit the worst A1 bottlenecks personally in the next few days, to ram home the importance of the scheme.

A ‘Dual the A1 Campaign’ has demanded urgent action, pointing to surveys of business leaders that have criticised the single lane A1 as “a key barrier to growth”.

In the interview, Mr Alexander said: “What you really want is the A1 to be a connection that runs from England to Scotland and back again at a high standard over the whole route.

“That would be a good thing for the economy of Scotland and the economy of England and the North-East of England. That to me is the right ambition for the route.

“Precisely which bits we are able to do when and how that gets phased - those are good questions which you will find out the answers to in the Autumn Statement.”

Pledges to dual the A1 date back at least as far as Tory Transport Secretary Malcolm Rifkind in 1992. Tony Blair also vowed to make it a priority – calling the road “terrible”.

However, under Labour, experts pointed to low traffic flows and concluded there was no “adequate justification, on economic grounds, to dual the whole of the remaining A1 north of Newcastle”.