Quarrelling parents who fail to resolve their arguments are leaving their children at risk of long-term mental health problems, new research has found.

Exposing children to constant feuding can also cause physical problems in youngsters such as headaches and stomach pains as well as affecting their growth rate , experts have claimed.

The study by relationship charity OnePlusOne examined the differences between "destructive" and "constructive" conflict within the family home and looked at how it affected children.

Destructive conflict, such as sulking, walking away, slamming doors or making children the focus of an argument, puts youngsters at greater risk of a range of social, emotional and behavioural difficulties, researchers said.

Children react better when parents can relate to each other more positively during arguments and when conflicts are resolved, they added.

Dr Catherine Houlston, co-author of the book, Parental Conflict: Outcomes And Interventions For Children And Families, said: "We know that conflict is a normal and necessary part of family life.

"It's not whether you argue but how you argue which matters most to kids.

"Research suggests that over time, the impact of being exposed to arguing between their parents can put children's physical health at risk.

"Evidence has shown that headaches, abdominal pains and even reduced growth can be brought on by the insecurity a child can feel by seeing their parents at war.

"However not all arguing has a negative outcome. If a child sees his or her parents in conflict then work things out they understand it's possible for difficult situations to be resolved and they feel more secure.

"Evidence suggests that working with couples at an early stage in their relationship, or during times of change, we can modify destructive patterns of conflict behaviour."

University of Sussex Professor Gordon Harold, co-author of the book, said: "Today's children are tomorrow's parents.

"The psychological fallout from homes marked by high levels of inter-parental conflict can lead to negative behaviour and long-term mental health problems that repeat across generations.

"Effective intervention can help to break this cycle, improving outcomes in the short and long term."