PLANS to dual two key roads in Somerset could be scuppered if a third runway at Heathrow Airport is cancelled.

A proposed third runway at London’s busiest airport was ruled illegal by the Court of Appeal in late-February, with judges arguing it did not take into account commitments made in the Paris agreement for tackling climate change.

Highways England has put forward detailed plans for dualling the A303 between Podimore and Sparkford and the A358 between Taunton and Ilminster.

But progress on either scheme is now on hold while the government “considers any further implications” of the Heathrow ruling.

Plans to dual the A303 were formally submitted to the Department for Transport in mid-June 2018, following a lengthy process of consultation and a public inquiry conducted by the Planning Inspectorate.

Transport secretary Grant Shapps MP was due to publish his final decisions on the plans on December 12 – but this was delayed as a result of the general election called for that date.

Nearly three months on, Highways England has said it is no closer to knowing when such a decision will be taken.

A spokeswoman said: “The Planning Inspectorate has sent its report and recommendation to the transport secretary, and we await  this decision.

“The ruling on Heathrow is complex and the government is still considering any further implications.

“We support the government’s commitment to meeting carbon targets, and we ensure that where possible we protect and maximise the contribution to the environment as part of our decision-making.”

The scheme to dual the A358 between Junction 25 of the M5 near Taunton and the Southfields roundabout near Ilminster is at a much earlier stage.

Highways England announced its preferred route for the scheme in June 2018, and is currently planning a second round of public consultation.

After this is completed, plans will be formally submitted to the Planning Inspectorate and another inquiry will be held – provided the government does not pull the plug on the scheme as a result of the Heathrow ruling.

A spokeswoman said: “Since we announced our preferred route last June, we’ve been carrying out surveys to help inform the scheme design ahead of consultation.

“In September we held our second community liaison forum and asked the members of the forum to give feedback on the route to help us develop the scheme design. We’re continuing surveys that will help inform our future scheme design.

“We’re also carrying out a procurement exercise to appoint a new supplier to take the scheme forward through the statutory phase and into construction, and we’ll hold another forum once the new supplier is on board.”