Environmental campaigners have told MSPs they face the "first real world test" on meeting emissions reduction targets at Holyrood this week.

It comes ahead of a vote on Wednesday on the Transport (Scotland) Bill which would introduce measures such as handing power to local authorities over introducing low emission zones and implementing a workplace parking levy.

The Bill also includes provisions designed to help improve local bus services, raise the standard and quality of roadworks in Scotland and extend smart ticket arrangements on public transport.

Gavin Thomson, from Friends of the Earth Scotland, said the vote would be a test for MSPs after the Parliament last month voted to reach net-zero emissions by 2045.

"MSPs committed to rapidly bring down Scotland's climate emissions," said Mr Thomson.

"The final stage of the Transport Bill represents the first real world test of whether they're willing to realise these increased ambitions.

"There is an opportunity for the Transport Bill to help Scotland, particularly our cities, transition to greener transport, improving our air quality and reducing our climate emissions."

Mr Thomson also suggested that one of the most keenly-debated aspects of the Bill, on the workplace parking levy, had been distorted by opponents of the move.

He said: "Of all the proposals within the Bill, the workplace parking levy powers have received the most coverage, and the most cynical distortion.

"Workplace parking levies have a track record of bringing much-needed investment to transport infrastructure and creating healthier places to live and work.

"They are an optional power being offered to councils and Edinburgh and Glasgow councils both formally asked the Scottish Government for this tool to cut traffic.

"It won't be right for every area, but it will combat congestion and air pollution in our city centres.

"If MSPs are prepared to follow through on their climate commitments, they need to recognise this means changing our polluting, dangerous transport system."

Scottish Conservative transport spokesman Jamie Greene said that his party would be prepared to back the legislation - however, not without the parking levy being scrapped.

"This regressive tax will harm the most vulnerable in society and punish hardworking people right across the country, which is why we tried to exempt hardworking emergency services, teachers, those on low incomes, the disabled and night shift workers," said Mr Greene.

"If the SNP wants our support with its Transport Bill, it can get it - but the car park tax must be scrapped now.

"This isn't about localism or tackling climate change, if this tax was so important to the SNP why wasn't it in the original bill presented to parliament?

"This has the potential to be one of the most-hated policies brought in since the SNP came to power and has been roundly criticised from all quarters.

"It's time for the SNP to swallow its pride and ditch this proposal so we can pass a decent Transport Bill which sticks to its original objectives."

A spokesman for Transport Scotland said: "The Transport Scotland Bill will lead to improved journeys for the travelling public and help deliver the cleaner, smarter and more accessible system that we all want to see.

"It is designed to improve bus services and clean up the air in our towns and cities as well as address pavement and double parking.

"Following a Green amendment, the Bill does include discretionary powers for local authorities to introduce a workplace parking levy.

"This will give councils another tool to help address the climate emergency should they choose to use it."