Sian Berry, from the Campaign for Better Transport, explains why it believes high air pollution levels could scupper the government's plans to upgrade the A14.
Plans to upgrade the A14 have come under fire yet again today from both MPs and a transport campaign group.
The Campaign for Better Transport says widening the roads around Brampton, near Huntingdon, and Bar Hill, near Cambridge, will cause an unacceptable increase in air pollution.
At the same time, a group of the region's MPs told a Commons debate that making part of the route a toll road would damage businesses in the region.
Elodie Harper has the story.
The government has talked down claims its plan for the A14 would lead to breaches of air pollution limits.
The Campaign for Better Transport said the proposals, which include creating a toll road between Huntingdon and Cambridge, would "seriously worsen" air quality for people living nearby.
But a Department for Transport spokesman said: "The proposed changes to the A14 will move long-distance traffic away from Huntingdon and help to improve air quality there, not make it worse.
"The government understands the impact a national road project like the A14 can have on air quality, and that is why a full environmental assessment will be completed before any work happens."
A transport campaign group has warned the government's plans to upgrade the A14 could be scuppered because they fall foul of air pollution limits.
Siân Berry, from the Campaign for Better Transport, said breaching those legal limits would attract big fines from the EU.
The region's MPs have spoken of their opposition to the government's plan to upgrade the A14 during a Westminster Hall debate.
Suffolk Coastal's Therese Coffey and Ipswich MP Ben Gummer are among those to have raised objections so far.
They say Suffolk is united in its concern about the plans which the MPs claim will be a tax on the area's drivers.
The government's plan to upgrade the A14 includes creating a new £1.5 billion toll road between Huntingdon and Cambridge.
The debate is taking place at Westminster at the moment with transport minister Robert Goodwill answering questions.
Plans aimed at tackling congestion on the A14 could leave the government in breach of legal limits for air pollution, a campaign group has warned.
Westminster's £1.5 billion proposals for the stretch between Cambridge and Huntingdon include widening parts of the carriageway and a 12-mile toll road.
But the Campaign for Better Transport is warning the scheme would not only significantly worsen air pollution across a wide area - it could actually push a number of locations above current EU legal limits.
Sian Berry, the CBT's roads and sustainable transport campaigner, said: "It would be far more cost effective and sensible to look at ways of reducing traffic levels to help solve congestion more permanently and sustainably without breaking the law and damaging public health."
The government's consultation on the project has recently closed and an announcement on the preferred route is due later this year.
The Deputy Prime Minister, Nick Clegg has told ITV News Anglia, that he believes tolling the A14 at Huntingdon is a fair way of ensuring the road is paid for.
Speaking at the Liberal Democrat conference in Glasgow, Nick Clegg said the A14 must be upgraded to boost the economy in the east.
A Northamptonshire MP has hit out at plans to demolish the Huntingdon viaduct as part of a £1.5 billion upgrade of the A14.
Northampton South MP Brian Binley said he welcomed plans to improve the road, but questioned the reasoning behind the demolition, which was paid for with taxpayers' money.
The news that the A14 will be a toll road has caused some anger amongst drivers.
Anglia News spoke to Roads Minister Stephen Hammond and asked him to respond to the suggestion that drivers would be forced to pay the toll.
Detailed plans for the new toll road on the A14 have been made public, but there are fears the charge will prompt motorists to find rat runs through nearby towns and villages.
The A14 is a vital route for commuters and freight traffic and is one of the most congested.
The Government says the answer is to build a £1.5 billion upgrade between Cambridge and Huntingdon, including a new 12-mile road toll, but not everyone is happy. Matthew Hudson reports.