The route will be added to the Department for Transport’s programme of major projects – but construction work will not begin until 2018 at the earliest.

Work will include a new bypass to replace the existing road around Huntingdon and upgrades along the A14 as far east as Milton.

Two new roads would be built either side and parallel to the current A14 immediately north of Cambridge for local use.

The existing A14 carriageway will be upgraded through the removal of accesses and junctions, and improvements to junctions at the northern and southern ends.

Funding will be partly generated through tolling a 20 mile stretch of the enhanced A14.

Transport Secretary Justine Greening said: “The A14 is a crucial strategic route for the east of England, vital not only for international road traffic using the port of Felixstowe but everyone who relies on it daily.

“This is why my department has been working hard to generate innovative and imaginative solutions to tackling long term congestion and I am pleased to be able to unveil what we believe to be the best option for people living locally as well as those who see it as a lifeline to international markets.

“It demonstrates yet again that this coalition government is focused on delivering economic growth and our determination to do everything we can to support delivery of key national infrastructure.”

The A14 road improvement package includes:

• Widening of the Cambridge Northern Bypass between Milton and Girton and enhancement of the Girton Interchange;

• Provision of high standard roads for local traffic use running in parallel to an enhanced A14 carriageway between Girton and the area near the current Trinity Foot A14 junction;

• Construction of a bypass to the south of Huntingdon between the area near Trinity Foot and the A1, at both ends tying in with the existing A14.