Jackie Baillie has stressed that a full and proper appraisal must be carried out on the plans to improve the A82 from Tarbet to the north.

The long-running plans to develop a new route were discussed during a meeting of the Scottish Parliament’s Citizen Participation and Petitions committee last week, during which Ms Baillie spoke in support of the petition.

The Helensburgh and District Access Trust petitioned the parliament, backed by more than 600 people, for the high road option between Tarbet and Inverarnan to be implemented.

However Transport Scotland’s preferred route would be beside the loch including the road being widened and viaducts being built over the loch, which Ms Baillie believes would be “catastrophic” to the environment.

The Dumbarton constituency MSP said: “This is too important an issue not to get right.

“This is not just a transport project but it is a project which will benefit those living in and visiting the national park.

“It is also of critical importance to hauliers and will have an impact on the economy and life of people living in Tarbet and Ardlui.

“The option presented by Transport Scotland would see big swathes of road going out over Loch Lomond, which would be catastrophic.

“There needs to be a full and proper appraisal carried out of the high road option which is favoured by local people and would protect the lochside.

“The A82 is a busy and dangerous road and we are now facing yet another summer season where people’s safety is put at risk because of the lack of progress in overhauling this route.

“The Scottish Government must act on this and ensure a full STAG appraisal is carried out to make sure the high road option is properly considered and implemented.”