The 15-year-old Logan Park High School pupil was selected by Mr Peters to represent him in Youth Parliament 2013.
''They will be big shoes to fill. He's the best-dressed man in politics,'' Jacobi said.
''He's been in the politics game so long now and his achievements have been so varied.
Jacobi said he would be spending a lot of time during the next month talking to other young people in Dunedin schools and communities so he could bring their perspectives directly to the heart of New Zealand's democracy.
''I've also got my suit at the dry-cleaners now, and I'll spend a wee while polishing my shoes as I work on my barbs and quips, which will be aimed at the other youth MPs.''
Jacobi said he was selected to represent Mr Peters after winning a Facebook competition.
Mr Peters asked pupils to make a political comment on the website, and the comment with the most ''likes'' earned the writer the right to represent him at Youth Parliament.
''He has always said politics is like a popularity contest. That's why he did it.''
Jacobi will be joined by six other Youth MPs from Otago secondary schools.
They are Bokyong Mun (Otago Girls' High School), representing Dr David Clark; Injy Johnstone (Kaikorai Valley College), representing David Parker; Kate Gardner (Bayfield High), representing Clare Curran; Tim Shiels (John McGlashan College), representing Michael Woodhouse, Eden Brown (Mt Aspiring College), representing Jacqui Dean; and Olivia Adam (Tokomairiro High School), representing Bill English.
Each member of Parliament selected a person aged 16-18 to represent them and their community at Youth Parliament on July 16-17.
Youth Affairs Minister Nikki Kaye said Youth Parliament was an opportunity for young New Zealanders to have their say on the big issues and to share their hopes and aspirations with MPs, Government officials and the public.
While at Youth Parliament, Youth MPs would sit on select committees, attend caucus meetings, ask oral questions of Cabinet ministers and engage in legislative and general debate in the House, she said.
''As well as representing their community at Youth Parliament in July, Youth MPs will hold their position from 1 May to 31 December 2013.
''During this time, they can actively engage with their community to gain an understanding of the ideas and concerns of young people. They can then lobby their MP to ensure they hear those views.
''The point of this is to ensure young people understand government and learn how they can influence decision-making,'' she said.
