Two grandparents have spoken of their heartbreak at not being allowed to see their only grandson as they called for the law to be changed.

Speaking at the Scottish Parliament's cross-party group on children and young people, Gordon and Shonia Mason wept as they told how they have been unable to see grandson Freddie since he was just five months old, nearly five years ago.

The couple, who are estranged from their eldest son, are now urging Holyrood to introduce a presumption in law for contact between grandparents and grandchildren.

Describing the situation as akin to "suffering a living bereavement", Mr Mason said: "We may never see our son and grandson again, but we hope if we can help push this forward and help others in future then it's worth it."

Mr Mason said he was reported to police for harassment because they sent a text trying to wish the child a happy birthday.

They have to try to send Christmas cards to Freddie via their son's solicitor, he said.

"I worry every day how Freddie is," Mrs Mason said.

"I would like to give my grandson Freddie as much love as was given to me by my grandmother, and the love my father gave to our son.

"Even at a few months old, he (Freddie) has an extra-big smile for his grandad Gordon."

The meeting, organised by YouthLink Scotland and Children in Scotland, also heard evidence from numerous experts in family law, academics and charities.

Simon Stockwell, head of the Scottish Government's family law unit, said the issue of giving grandparents the presumed right of contact was considered - and rejected - in 2006.

He said: "The fundamental presumption in law is that the welfare of the child is paramount and the Government is reluctant to move away from that position.

"Grandparents vary, of course, and it should be looked at on a case-by-case basis."

Mr Stockwell said in a Government consultation about whether children should have the presumption of contact with their grandparents, 47% of respondents were in favour, 38% were against, while 14% did not answer the question.

A child-only questionnaire showed 78% of children thought it was important to keep in contact with their grandparents, the third highest answer after parents and siblings.

Beth Anne Logan, who spoke of her experience being estranged from grandparents, said: "There are no rights that should be able to supersede those of the children, and children being able to express their views.

"With the child survey we've heard very clearly and very consistently that 78% of our children want to have a relationship with their grandparents, so we need to honour that.

"As adults, we complicate things and actually to children it's quite simple - 'I want to see my gran, I want to see my grandad'."

Roseanna MacDonald, from Scottish Women's Aid, thanked the Masons for their testimony but warned: "When it comes to contact with grandparents, in the context of domestic abuse, we believe that the proposal ... will inappropriately shift the focus away from the welfare of the child and inadvertently increase risk."

June Loudoun, speaking for the Grandparents Apart charity, said: "Without a change in the law, we will continue to be cast aside.

"Children should not be torn away from family surroundings, unless those surroundings are unsafe."