One in seven grandparents in Britain is being prevented from seeing their grandchildren, new research has found.

And nearly a quarter reported that they had been excluded from their grandchild's life after the child's parents had divorced or separated.

A further seven per cent said they had been intentionally frozen out by their own daughters or sons, or their children's spouses.

Missing out: One in seven grandparents are being blocked from seeing their grandchildren, new findings have shown

The survey of more than 2,000 grandparents showed that those in the North East had been worst hit by the trend, with one in three reporting access to their grandchildren had been restricted.

A similar number of grandparents living in London said they too had been stopped from spending time with their grandchildren.

Fourteen per cent admitted only seeing their grandchildren every few months, with distance cited as the main reason for the infrequency of visits.

Legal cases: Grandparents are prepared to pay tens of thousands of pounds just to re-establish their relationship with their estranged grandchildren, legal experts have said

Leading family lawyer Vicky Preece revealed that more and more grandparents are now taking legal action to gain access to their estranged grandchildren.

Ms Preece, from IBB Solicitors in West London, which commissioned the study by Atomik Research, said: 'In the past ten years, I've seen a rise in cases of this kind.

'I deal with about 20 cases a year and I would say up to half have an element of grandparents being estranged from their grandchildren.'

And she warned: 'Some grandparents are paying out quite substantial legal costs.

'If you end in fully contested private proceedings, you are talking tens of thousands of pounds.'

Ms Preece claimed the research highlighted how family relations had broken down across the country.

She said: 'One aspect that has become apparent to me in handling these cases is family breakdown, where one parent is using the children to get back at the other parent and the grandparents get caught up in that.'

Last night, Childline founder Dame Esther Rantzen called for the right of grandchildren to see their grandparents to be enshrined in law.

'A living bereavement': Dame Esther Ranzen described being apart from grandchildren as 'a real loss'

Dame Esther said: 'This is a child's right. I am aware that not all grandparents are saints, so there can be a good reason why a child is being excluded. But not in these numbers.

'The experience of many of the children who ring Childline is that grandparents are a place of safety and security if things are going badly wrong in the parental life.'

Dame Esther added: 'Estrangement from their grandchildren has been described to me by grandparents as a living bereavement and by grandchildren as a real loss. I've heard, for example, of a grandson who was even prevented from saying goodbye to his grandmother when she was dying.'

Diana Dunk, 73, from Oxfordshire, said she had not seen her three grandsons for almost four years due to strained relations with her daughter-in-law.

Heartbreaking: Grandparents say its a real struggle to be apart from their loved ones after their in-laws have stopped contact

Ms Dunk described how she had been excluded from the children's birthdays, Christmases and family holidays.

Even pleas to attend one grandson's cricket matches had been turned down.

'I never thought that I would not have a natural relationship with my grandchildren,' Ms Dunk said. 'When you have grandchildren, it's an unconditional love. It's a very special relationship and when it's taken away, it's just a travesty for the grandparent and the grandchild.

'It breaks your heart – you feel very isolated and alone. Unless people have been through it, they don't understand.'