They pass laws which could send people to jail, but many MSPs have never visited their local prison.

Even those who have, are unlikely to have done it by public transport.

But Scotland's politicians are being urged to go behind the gates to experience the problems prisoners' families face visiting loved ones behind bars.

A charity is urging them to try to accompany a family from their constituency - and ditch the car to get an authentic experience.

Families Outside, the national charity which supports families affected by imprisonment, says maintaining family links is often crucial to efforts at tackling offending and rehabilitating inmates. Research has consistently shown prisoners who have regular contact with their families are up to six times less likely to reoffend.

Visits can also protect children who have a parent in prison: Studies have found these young people are three times more likely to suffer significant mental illness.

The charity also argues it is important children are not punished unnecessarily by a prison sentence for the crimes of a parent.

So far 13 MSPs have signed up to the scheme which is being held to coincide with the Year of Young People. Families Outside aims to take MSPs on a tour of the prison, the visitor services, and the family support initiatives so they can see for themselves the challenges that families face as well as the best examples of work to support them.

Professor Nancy Loucks, chief executive at Families Outside said the charity knows of one father in Shetland who regularly undertakes a 24 hour round trip so his daughter can visit her mother in HMP Grampian. That is an extreme example, she admitted, but added: "Even visits on the mainland can take significant time depending on where the family is in relation to the prison. Trying to complete these journeys with children can make them even more challenging.

"Anyone who has children of their own will have faced similar experiences, but instead of ending up at a zoo or a theme park, you end up at prison security where you, and the rest of your family, are then searched and surveilled.”

"These children and families are not guilty but in effect serve the sentence alongside the person in prison."