Mr Chauvel, 37, leaves behind a successful legal career to take his place in Labour's caucus when rural and trade veteran Jim Sutton retires on August 1.
Yesterday Mr Chauvel was excited about his new job within Labour, the political party he joined at 15. But the gay MP does not welcome questions about his family, which includes a 1-year-old son.
"I understand that people may think that they have some right to know about my personal situation because I'm an MP, but I don't agree with that," Mr Chauvel said last night. "I think that there are personal privacy issues involved."
Mr Chauvel is co-chair of Labour's Rainbow Sector Council, the party's gay wing. He lives with his partner of 11 years on Wellington's Oriental Parade and speaks proudly of his son. But that is as far as he thinks people's fascination with the issue should go.
"I'm not going to jeopardise my son's privacy, or his mother's, or her partner's," he said.
"The reality is that there are two parents, but four people who care very much about him and want to put his welfare first.
"What I would love to see is people asking me about my views on economic and social policy, and evaluating whether I'd be a good MP from the point of view of keeping us internationally competitive and socially just."
Since completing a law degree in 1989 Mr Chauvel has carved out a career that includes being made a partner at Minter Ellison at 30. He has worked in public and human resources and industrial relations law and held commercial directorships.
"I'm not frightened of hard work," Mr Chauvel said.