Tory MIles Briggs said motorists had been subjected to “countless hours of unnecessary congestion” at the Sheriffhall roundabout because of the long delay in starting work on the proposed flyover.

He said: “It’s ridiculous that after nearly 20 years of discussion and more than £6m in consultation, Sheriffhall continues to bring the Edinburgh Bypass to a standstill every rush-hour.

“From day one it was clear that the roundabout needed a fly-over; 40 years later we have a significantly larger population across the region but have seen no progress whatsoever to improve the roundabout.”

Funding for he junction revamp was included in the Edinburgh and South East Scotland City Regional Deal announced in July 2017. But the £120 million price tag attached to it at that time is certain to have increased dramatically.

Ground Investigations were carried out in 2018 and draft road orders were published in 2019.

But in 2020 the plans were put on hold to allow a review of the project as part of a Scottish Government budget deal with the Greens.

A public local inquiry was eventually held in early 2023 and the report, delivered to the Scottish Government in early 2024, is still under consideration by ministers over a year later.

In a Scottish Parliament debate in 2018, Mr Briggs highlighted the economic value of the City Bypass and warning that gridlocked traffic was putting off potential investors to the area. He cited a report by Inrix which identified the bypass as the most congested trunk road outside London and predicted that the cost of bypass congestion to the economy could reach £2.8 billion by 2025.

Now Mr Briggs has launched an online campaign, which will encourage the public to make their voice heard and put pressure on the government to provide a renewed commitment to this project.

He said more than 75,000 vehicles used the bypass every day already, but that was set to increase since Lothian has the fastest growing population in Scotland and is forecast to account for 84 per cent of Scotland’s predicted population growth over the period to 2033.

He said: “Sheriffhall is costing commuters and businesses in our region time, money, and pollution from congestion.

“However, due to Green party opposition and SNP complacency, proposals have been left to gather dust while costs increase.

“It is time for SNP ministers to act and provide the leadership needed to get the upgrade back on track.

“That is why I have launched my campaign to upgrade this notorious junction, asking residents across Lothian to make their voice heard.

“Edinburgh and the Lothians deserve better than this and I hope my campaign to upgrade the junction will make SNP ministers understand the level of frustration motorists are facing and give the upgrade the priority it deserves.”