A Holyrood committee has raised concerns about the tight timescale for implementing low emission zones (LEZs) in Scotland.

MSPs on the Environment Committee said they supported the move but questioned whether councils had the necessary technical and financial resources to operate them within the suggested timeframe.

Scotland's first LEZ is due to be up and running in Glasgow by the end of the year with zones in place in Aberdeen, Dundee and Edinburgh by 2020.

The report said that even if the zones were in place by the deadlines "they will not be enforced for a number of years".

MSPs called for a progress update by the end of June 2018 "along with an indication of the date of which they will be enforceable".

The committee backed private cars being included in the LEZs and urged ministers to consider exploring congestion charging and workplace parking levies.

MSPs also noted concern that at the current rate of progress it would take around 239 years to reach the government's target for 10% of journeys to be made by bike by 2020, while passenger numbers on buses have fallen over the past five years.

Committee convener Graeme Dey MSP said: "Poor air quality remains an issue in a number of our towns and cities across Scotland, and effective change is needed now so that all of us can breathe clean air and lead healthy lives in the future.

"While we recognise that the Scottish Government has ambitious targets to tackle pollution, we have questions on whether the necessary support is going to be in place to achieve these.

"For example, while we support low emission zones and the phasing out of cars to stop toxic and traffic-choked streets, we are seeking clarity on how this will be delivered."

Emilia Hanna, air pollution campaigner for Friends of the Earth Scotland, welcomed ongoing efforts to tackle deadly air pollution in Scottish cities.

She said: "People continue to die in their thousands because we are failing to meet (EU air quality) standards.

"Low emission zones are a vital tool which will make our air cleaner and safer to breathe if they are delivered properly.

"As Glasgow City Council develops its plans for the first low emission zone, due by the end of this year, it needs to set an ambitious example ahead of the Aberdeen, Dundee and Edinburgh LEZs due in 2020."

Ms Hanna said she "particularly welcomed" the committee's recommendation that private cars should be included in low emission zones.

"An LEZ which only includes buses would be very disappointing and would not deliver the step change on pollution that we need," she added.