ACT Party Leader Don Brash said he was extremely sorry Mr Boscawen was stepping down from the ACT Party list but said he totally understood his colleague's reasons.
"John is a person who is not willing to give less than 100 per cent of his time to the job, and he now feels he needs to devote the same level of commitment to his family," Dr Brash said.
"He has done an extraordinary job over the past three years, advancing ACT's principles and pursuing his portfolio responsibilities with a level of passion and commitment that is quite exceptional.
"I'm very pleased that John is going to be campaigning with us up until the election. That will be a huge asset, and I know he will continue to be a great supporter of ACT in the future."
Mr Boscawen said he wanted to thank all of his caucus colleagues for the support they have given him in Parliament, especially since he became Parliamentary Leader.
"In particular, I would like to acknowledge Sir Roger Douglas, who so strongly encouraged me to stand for ACT in the first place, and Rodney Hide, who has given me invaluable support and assistance throughout my parliamentary career.
"I wish Don Brash, John Banks, and the rest of the ACT team every success in the election and I intend to work hard to help them achieve that success by campaigning for the Party vote in Tamaki. I plan to remain very active in the Party beyond the election," Mr Boscawen said.
The ACT Party board will meet next Saturday to make a decision on how this will affect other list rankings.