National last night chose Matthew Doocey to contest the Christchurch East byelection.
The vacancy will be created when Labour MP Lianne Dalziel resigns shortly to stand in the Christchurch mayoralty on October 12.
Mr Doocey, aged 41, is a healthcare manager working at the Canterbury District Health Board.
He returned to Christchurch from Britain this year.
Regional National Party chairman Roger Bridge said there were two nominees.
"While an incumbent Government has never won a byelection in a seat it does not already hold, the National family are united behind Matthew as he accepts the challenge to wrest the seat which Labour has held since 1922."
Lianne Dalziel had a majority of 5334 in 2011 but National polled 4152 higher than Labour in the party vote.
Six Labour nominees will seek selection in a contest on September 21.
The nominees are James Caygill, a manager with Ngai Tahu; Karen Hayes, a nurse and community worker; Christina Laalaai-Tausa, a part-time political science lecturer; Tina Lomax, principal of Kingslea School; Deon Swiggs, a community advocate; and Poto Williams, regional manager of St John of God Hauora Trust.
The 19-year-old was found in a remote area in the hills of Upper Hutt.