The Scottish Government has been urged to lower the speed limit in residential areas to 20mph to save lives.

Charities and public health organisations have written to First Minister Nicola Sturgeon calling on her to "seize the opportunity" to support the Safer Streets Bill, which is currently being scrutinised in the Scottish Parliament.

Lower speed limits, particularly 20mph in urban areas, save lives and are proven to reduce the number and severity of injuries on the road, they said.

The groups added Scotland needs to lead, as it did in banning smoking in public places and reducing the alcohol limit for drinking and driving, and the Bill offers "the best chance of safer, fairer roads".

Adrian Davis, professor of transport and health at Edinburgh Napier University, said: "There is strong evidence that 20mph limits have had a positive impact on public health where they have been introduced.

"There is consistent and convincing published research that shows 20mph speed limits reduce collisions, injuries, and motor traffic speed, all important public health concerns in Scotland."

Signatories to the letter include Chest, Heart & Stroke Scotland, Cycling Scotland, Friends of the Earth Scotland, Living Streets Scotland, Poverty Alliance, the Royal College of Paediatrics and Child Health, Transform Scotland and Edinburgh Napier University Transport Research Institute.

Professor Steve Turner, officer for Scotland at the Royal College for Paediatrics and Child Health, has previously outlined the organisation's support for 20mph limits.

He said: "I urge local authorities in Scotland to introduce 20mph speed limits in built-up areas in order to create safe and healthier environments for children to walk, cycle and play in."

The Bill was introduced by Scottish Green MSP Mark Ruskell last year.

Transport Scotland said local authorities in Scotland can and do implement 20mph limits where the situation calls for them, such as around schools or in areas used by high numbers of pedestrians.

In their letter, the 25 organisations say a national approach offers benefits such as being more cost-effective and more equitable.

A Transport Scotland spokesman said: "We share the view that 20mph speed limits are a good idea when implemented in the right environment.

"However, we believe, and it is shared with many local authorities, that more evidence and further consideration needs to be given to the impact and consequences of a nationwide default 20mph limit, including an assessment of Scotland's road network before the measure proposed in the Bill can be fully supported."