Plans for a £120 million redevelopment of a roundabout on the Edinburgh city bypass will increase congestion and should be stopped, the Scottish Greens have claimed.

The party has launched a campaign opposing the proposal for a flyover at the Sheriffhall roundabout, arguing the money should instead be spent on bus lanes and public transport in light of the climate emergency.

The junction, which lies in south-east Edinburgh on the city bypass, has been earmarked for redevelopment since 2013 and the preferred plans would see a flyover built to try and reduce congestion.

READ MORE: Flyover planned for Edinburgh bypass bottleneck

Despite assurances from the Transport Secretary that the development would improve road safety and cut journey times, the Greens’ co-leader Alison Johnstone has said the proposal will increase the amount of traffic.

The Lothians MSP said: “The council estimates that congestion costs Edinburgh £225 million a year, yet they and the Scottish Government insist on repeating the same failed mistakes of the past.

“Since the 1960s we’ve known that if you build more roads, they fill up with cars. That’s why the proposal to turn Sheriffhall roundabout into a spaghetti junction isn’t an upgrade, it’s a step backwards, especially when we now know 60,000 cars are coming into the city every morning.

“This is the 21st century and we are in a climate emergency. £120 million could go a long way in transforming our capital for the future.

“It could pay for 120 miles of segregated cycle paths, for example. It could boost our bus lanes and park-and-ride offerings to get our city moving again, instead of sitting in gridlock every day.

“The SNP in Edinburgh council and Holyrood need to match their rhetoric with real transformative change if we are to build a sustainable future. That means ditching the failed old ways like spaghetti junctions.”

The campaign to block the flyover follows the party’s calls for a “transformative shift in public investment” in the upcoming Scottish Budget.

With the SNP relying on Scottish Green votes to pass the budget since losing their parliamentary majority in 2016, co-leader Patrick Harvie has put transport at the heart of his party’s demands.

In a letter to Finance Secretary Derek Mackay, Mr Harvie said that to win Green MSPs’ support the budget “must turn the rhetoric of a ‘climate emergency’ into a reality by increasing investment in the low-carbon economy”.

READ MORE: Increase in Queensferry Crossing traffic accused of boosting congestion

As well as citing the Sheriffhall roundabout, Mr Harvie also suggested that the money for dualling the A9 and A96 could be diverted to fund free bus travel for young people.

In earlier comments about the Sheriffhall development, Transport Secretary Michael Matheson said: “Sheriffhall roundabout is the only at-grade junction on the A720 Edinburgh City Bypass and is a well-known bottleneck, often the scene of significant queuing particularly at morning and evening peak times.

“The scheme design will see a new flyover arrangement for traffic travelling on the city bypass, separating local traffic from the strategic traffic on the bypass and will allow the traffic on the bypass to flow freely, improving road safety and journey times for all road users.”