The eve of the London 2012 Olympics is finally here. For the next two weeks we will all be cheering on Team GB, hoping our athletes will realise the Olympic dreams they have trained so hard for.

But I hope they will not be the only winners of these Olympic Games. I hope the 180 million children who are currently suffering from the hidden hunger crisis - known as stunting - will be able to steal some of the limelight too.

Stunting occurs when children don't get the right nutrients in the first 1000 days of life and is the silent crisis crippling the potential of millions of children. It stops a child developing mentally and physically. It stops them from achieving their full potential and from growing up to achieve their dreams. The damage is irreversible. Once inflicted, there is no cure.

Everyone has seen images of starving children on their TV screens and it is painful to watch. I have seen the effects myself during a trip to Sierra Leone with UNICEF four years ago. The faces of the acutely malnourished children I met there were so frail and thin that I don't think the imprint of their images will ever leave me.

As a proud dad I can't imagine what it must be like as a parent to see your child suffer in this way. But that is the harsh reality right now for the hundreds of thousands of children living across East and West Africa who are in the grip of a slow burning hunger crisis that has been unfolding for years. Their prospects are bleak.

I have been a Goodwill Ambassador for UNICEF for seven years and I am incredibly proud of the work they do to save and protect children's lives. As a global leader on child nutrition they are helping children and their families living in many of the world's poorest communities, to improve the nutritional value of their food so that they can keep their children healthy.

But they cannot do this alone. Tackling the issue of stunting is huge and challenging but not insurmountable if our government continue to play their part.

So today I paid a visit to the Prime Minister David Cameron to ask him to help change this. To welcome his leadership and urge him to continue to help reduce the number of children suffering. I called on him to put child hunger and stunting at the top of the political agenda, starting with the Global Nutrition Event he will chair on the 12th August, the eve of the Olympic closing ceremony and continuing into 2013 when the UK hosts the G8.

I was not making my point alone. The letter I delivered to David Cameron was co-signed by over 50 fellow global UNICEF Ambassadors, supporters and stars from the world of sport and entertainment who all wanted to use their name to speak up for some of the world's most vulnerable children. Ewan McGregor, Vanessa Redgrave, Liam Neeson, Robbie Williams, Claudia Schiffer, Whoopi Goldberg, to name but a few. The list goes on and on and on.

And I am asking you, to add your name too.

The Olympics is all about people achieving their personal best and reaching their full potential in life. Lets make this Olympics the time to ensure that all children can too.

Visit www.unicef.org.uk/hunger to add your name to the letter now or text HUNGER to 78866 .

In the lead up to the Global Nutrition Event on August 12th UNICEF, alongside other organisations, is calling for urgent action on child hunger and stunting.