MSPs have backed a controversial car tax that could hit hundreds of thousands of workers in Scotland.

The SNP's Richard Lyle, formerly a critic of the levy, was criticised after changing gear on the policy on Wednesday with Labour calling the Uddingston & Bellshill MSP's new stance, a “spineless, shameful U-turn”.

The move would allow local authorities to choose to introduce a levy on parking as part of measures to reduce congestion and tackle air pollution.

The Workplace Parking Levy (WPL) could see motorists who drive to work having to pay hundreds of pounds a year for a parking space.

The plan is opposed by Labour, the Lib Dems and the Conservatives.

READ MORE: Concerns raised over proposed workplace parking levy in Scotland

What is the Workplace Parking Levy?

The SNP pledged to allow councils to intorduce a WPL as part of its budget agreement with the Greens.

Employers would pay an annual tax to the council for every employee parking space and could choose to pass this cost on to staff.

An amendment to the Transport (Scotland) Bill currently going through parliament would hand powers to the 23 councils who would each decide to impose it or not.

Where will it apply?

Glasgow City Council and City of Edinburgh Council have expressed an interest in introducing the charge inspired by a similar scheme introduced to Nottingham in 2012.

There, the city charges firms with 10 or more parking bays £415 each per year with half of large employers choosing to pass on the cost to staff.

It had been estimated that commuters driving to and from work accounted for about 70% of peak time traffic in Nottingham with the tax raising around £9m a year since it started - with the money going towards building sustainable traffic networks.

How will it work?

Details haven't been hammered out yet as councils will have a final say on the rate they choose to charge employers.

The rates charged in Nottingham increase each year in line with inflation.

The levy will be paid to councils through monthly instalments, annual invoice or direct debit and will be charged by all employers.

City of Edinburgh Council has estimated the tax could raise between £9 million and £15 million a year.

READ MORE: SNP MSP Richard Lyle accused of ' spineless' U-turn on parking tax

Does it apply to everyone?

Under the Scottish scheme, hospitals and GP surgeries would be automatically exempt, but it would be left to individual councils to decide on any other exemptions.

Other public sector workers such as teachers, police officers and social workers could have to pay.

In Nottingham hospitals and NHS premises are exempt, as are emergency services such as ambulance, police and fire services, and disabled parking spaces.

There, the charge doesn't apply to parking spaces for motorbikes, customer vehicles, or fleet vehicles parked at an employer's premise and delivery vehicles.