Two nine-year-olds have joined a national campaign to encourage more people to become organ donors.

Hannah O’Brien, who attends Kings Langley School and Grace Dowding, who attends Abbots Langley School, were among dozens of people congregating in Battersea Park, London, on Saturday sporting t-shirts and signs saying "I have", indicating they have signed up as organ donors.

NHS Blood and Transplant has released new figures showing that despite the fact that 82 per cent of people in England want to be organ donors, only 50 per cent have told their family.

The release of the new figures coincides with the launch of new leaflets and posters designed to encourage more people to make the decision to be an organ donor when and if they can, and to tell their loved ones their decision.

NHS Blood and Transplant also revealed that seven out of 10 people said if they didn’t know a member of their family wanted to be an organ donor they would not agree to donation if asked.

Anthony Clarkson, Assistant Director of Organ Donation and Transplantation at NHS Blood and Transplant, said: "We want to ensure that more people in the UK get the transplant they need and an important part of that is ensuring that everyone that wants to donate can.

"We’re delighted that so many people in the UK want to be organ donors but only 50 per cent of those who want to donate have told their family. If you don’t tell anyone your decision, how will your loved ones know what it is? Don’t make them guess at such a difficult time.

"When you’re next with your loved ones, have the conversation. Tell them that should the time come, you’d be proud to donate your organs. Then there will be no uncertainty."

Hannah can said: "I think organ donation is a really good thing because if you suddenly die, your organs are no use to you but they are to someone else - someone could need them.

"I have talked to my family, It’s a bit of a worry talking about it but if I didn’t tell them they could say no. Now they know.

"If you don’t like talking about it and want to be an organ donor, just say it once, just tell them."