All railway stations in Scotland should be "step-free" to improve accessibility, according to the Scottish Greens.

The party's transport spokesman, John Finnie MSP, said that the move would make it easier for people with mobility difficulties and families with prams and buggies to access stations.

A freedom of information request to Network Rail, made by Mr Finnie, indicated that only 40 of over 350 stations in the country are officially classified as "step-free".

In 2006, the Department for Transport (DfT) published the Railways For All Strategy, outlining the UK government's intention to improve access to the rail network for disabled people across Britain.

Scottish ministers, through Transport Scotland, worked in partnership with the DfT to identify Scottish stations that should be given priority for improving access for disabled people.

However, the Scottish Greens said that they are concerned that the programme for improving the remaining 310 stations is too slow.

Mr Finnie said: "The travelling public, including people with mobility issues and families using buggies and prams, deserve an easily-accessible public transport network as our railways are a public service.

"The Scottish Government is moving too slowly on this issue, and indeed there's an irony as the financial penalties incurred by ScotRail for poor performance under the Service Quality Incentive Regime help fund the necessary improvements.

"We clearly shouldn't be relying on a poor rail service to generate the cash for step-free stations and platforms.

"Scottish Greens want a public transport system that is accessible and affordable and we will continue to press for faster action on step-free stations."

A Transport Scotland spokesman said: "We work closely with colleagues in the Department for Transport to ensure that disabled people can fully engage with travel, and participate completely and without barriers in our society.

"As this is a reserved matter for the UK Government, the Department for Transport leads on the Access For All programme and The Secretary of State for Transport announced the continuation of this programme for the next control period.

"We have worked closely with ScotRail and Network Rail in developing a nomination list for stations for this next control period which has now been submitted for consideration.

"The list of proposed stations is based on the agreed set criteria set by the UK Government.

"In addition to the UK Government's Access For All programme, the Scottish Government continues to fund significant accessibility improvements across Scotland and with further schemes under consideration."