IT'S a grim subject. Currently, there are 2.5 million children in the UK (one in five) whose parents are alcoholic or hazardous drinkers. Last week, an all-party parliamentary group, in collaboration with the National Association for Children of Alcoholics, launched The Manifesto for Children of Alcoholics. A number of MPs and public figures, including MPs Caroline Flint and Liam Byrne, along with the Archbishop of Canterbury, Justin Welby, supported the launch by sharing their difficult and painful personal experiences of growing up with an alcoholic parent.

The aim of the manifesto is to ensure government takes responsibility for meeting the needs of children in alcoholic households by creating a national strategy which would include properly funded support for the young people, as well as awareness-raising and education for people who work with them.

We certainly need one. The statistics for these innocent victims are disturbing and shocking: they are four times more likely than others to develop alcoholism, three times more likely to consider suicide, five times more likely to develop eating disorders, twice as likely to have problems at school and with the police and, not surprisingly, six times more likely to witness domestic violence.

No wonder the problem is being called Britain’s "biggest secret scandal". The fallout from growing up with an alcoholic parent doesn't just impact on childhood years; it extends well into adulthood and can be lifelong.

The demands on these children are extreme because they are forced to live parallel lives, in two very different worlds.

On the one hand, there is Sober World, with a sober dad or mum at its centre. This world seems, at least on the surface, to be like everyone else’s: dinners get put on the table, washing and ironing gets done, homework gets checked and bills get paid. It’s great while it lasts but there is a fragility and unreality to this world because it can be shattered by the popping of a cork or the squeaking of a screw-top. Children with alcoholic parents are intimately familiar with the signals that mean their life is on the turn. They are forever vigilant and their peripheral vision is constantly scanning their domestic horizon for signs of trouble.

Enter, stage-left, the scary monster world of the drunken parent. This is no make-believe horror movie, but a day on day, night on night, real-time narrative of anxiety and fear. There are no heroes, only drunken villains who shout, lurch, scream, kick, collapse, punch, lament, accuse, abuse, delude, deny and forget.

This is the Land of Lack. The lack of breakfast because there is no cereal or milk; the lack of dinner money because it all got spent on booze; the lack of friends because your pals can't be brought back for tea or for a sleepover (just in case). The lack of safety and sanity. The lack of proper, consistent love.

On the flip side, there is an abundance of anxiety, shame, confusion and guilt for the child of an alcoholic parent. And oodles of role-reversal where the child becomes an under-sized adult, and the drunk adult becomes an over-sized, dangerous baby. This is an unnatural world in which the child cooks, cleans, manages finances, changes nappies, reassures, soothes and tells the parent the monsters are not really there (they're just imagining them). It is hell for the child, with nobody to tell, nobody to rescue them, no escape. Instead, these children must tie their hearts and minds in knots, straddle two realities and, like swans paddling crazily under the surface, glide along as if everything in their world is going swimmingly.

Children are hard-wired to love and adore their parents and will try to protect them at all costs – even when their parents abuse them. Children need to be helped to understand that they are not to blame if their mum or dad drinks too much. To do this, we need to detox from our denial of the real and lifelong harm caused to families by alcohol abuse.

We cannot turn our backs on helpless and innocent children. If we do, we risk an ongoing legacy of alcoholism and its related problems cascading from one generation to the next.