Young people aged 16 and 17 are able to take part in the national initiative which allows them to take on new challenges in their local community and make new friends.
Harriett has written to local schools urging them to get involved in the initiative.
This year, it is expected that 90,000 young people will take part in the programme, which involves spending 30 hours working on a local social action project.
Harriett commented: “The National Citizen Service is a great initiative which helps teenagers to try new things and mix with people from different backgrounds.
“You take part in local group challenges and spend a short time away from home on taking part in exciting outdoor activities.
“I have written to local head teachers urging them to promote this initiative to their pupils and I hope that more people will apply to get involved this summer.”
People can find out more about the National Citizen Service by visiting www.ncsyes.co.uk/.