About 42,000 vehicles use the road every day

The plans involve widening the existing A74 at Carlisle into a three-lane motorway in both directions.

There would also be a separate road for local traffic on the stretch of road known as the Cumberland Gap.

The Highways Agency has received 27 objections to the plans. The public inquiry takes place on 27 September.

New bridge

The five-mile (8.4km) stretch of the A74 is the main route between England and Scotland and carries 42,000 vehicles a day, including around 10,000 heavy goods vehicles.

As well as widening the existing road, other work will involve building a new bridge over the River Esk to carry non-motorway traffic, and replacing the Mossband Viaduct, which carries the A74 over the West Coast Mainline.

Objectors are worried about the impact building work will have on surrounding countryside.

A spokesman for the Highways Agency said: "The public inquiry will be held by an independent inspector who will hear the evidence from all parties and then make recommendations to the Secretary of State."