Britain Stronger in Europe, the pro-Remain campaign, wants its younger supporters to send postcards to their older relatives telling them why they are voting for continued EU membership.
"We believe that the passion and enthusiasm of young voters can be channelled into getting their older relatives out to vote for Britain to remain in Europe," said Will Straw, executive director of the group.
The move comes after Prime Minister David Cameron appealed to younger people to back Remain earlier this month, stating their future opportunities are linked to membership.
Polling has shown that younger Britons are more likely to want to remain in the EU, and British universities have largely come out in favour of remaining in the EU, with over 100 university vice-chancellors signing an open letter in February outlining the role of the EU in supporting the UK's higher education institutions.
The tactic rings of the Ring Your Granny campaign launched in the buildup to the Irish referendum on gay marriage, in which younger people were encouraged to get their grandparents to support same-sex marriage.
However, Tom Pursglove, co-founder of Grassroots Out, hit out at the campaign, arguing that the EU has failed young people since its inception.
"My generation have seen their wages depressed by EU mass migration and have had to put up with taxpayer funded propaganda in their schools and universities.The EU is anti-democratic and has failed young people since its inception," Pursglove said.
"Young people are internationalists. They do not want to be confined to EU borders. They want the chance to work and live in countries around the world. By leaving the EU, we can strengthen our ties with countries in all four corners of the globe."