Charity Sustrans calls for city workplace parking tax
A workplace parking tax on large employers should be considered in Welsh cities, a charity has told BBC Wales.
Sustrans Cymru said city councils could tax firms for spaces provided for staff to raise money for public transport and encourage people to leave cars at home.
Employers could choose to fund the cost of the tax themselves or all pass on some, or all of it, to workers.
However, businesses said the tax could put off investment in Wales' cities.
Councils in Wales and England have the power to introduce a workplace parking levy.
Nottingham is the only council to do so, taxing larger employers with more than 10 spaces about £400 per year for each one.
It has raised £50m for sustainable transport projects since it was introduced in 2012 and the council says it has helped reduce emissions to target levels.
Steve Brooks, director of Sustrans Cymru, told BBC Sunday Politics Wales the Nottingham model could work in Welsh cities, as "car is king in Wales" and environmentally, the impact of over-relying on cars was huge.
"So we have to look at a ways to control traffic and keep our towns and cities moving and a workplace parking levy is an important tool in the armoury.
"The workplace car parking levy works in urban environments, so places like Cardiff, Swansea, Newport and Wrexham, this is an idea that should be considered.
"What we should be doing, is that any funds raised by things like congestion charges and workplace parking levies goes back into transport, so we reinvest in public transport - so people have real options to get out of their cars."
Scottish councils look set to get powers to introduce the Workplace Parking Levy as the Scottish Government is currently pushing legislation through the Scottish parliament, despite opposition from other political parties and business groups.
Ian Price of CBI Wales says if introduced by councils here, it would be another tax that would make Wales' cities a less attractive option in a competitive market.
"They've just taken the tolls off the Severn Bridge and it's easier to get to Bristol.
"There's some real dangers regarding that in Wales, certainly in some of the cities like Swansea and Newport at the moment where you're trying to encourage inward investment.
"Nottingham was a terribly congested city, but I don't think we're quite there in Cardiff yet and maybe Swansea to a certain extent.
"At the moment, I'd rather see us looking at how we improve the infrastructure, improve the roads we currently have, improve the public transport and look at other ways of encouraging people into the city, rather than trying to tax them off the roads."
A WLGA spokesperson said they were not aware of any councils in Wales with plans to introduce the tax - but over time they may wish to consider it.
Cardiff council included a workplace parking levy in a recent green paper and said it was still being considered - but it had to reduce CO2 emissions in the "shortest time possible" according to Welsh Government legal direction, and the levy would take time to plan and implement.
BBC Sunday Politics Wales is broadcast at 11:00 BST on 26 May and then available on BBC iPlayer.