Mr Hayes, 65, was first elected MP for Wairarapa in 2005. That followed a career as an agricultural economist and then as a diplomat, including a stint as New Zealand’s ambassador to Iran and Pakistan.
Before becoming an MP, he was best known for his part in the Bougainville peace process. He was made an officer of the New Zealand Order of Merit in recognition of that work.
He served as private secretary under former Labour trade minister Mike Moore and is currently parliamentary private secretary and chairman of the foreign affairs, defence and trade select committee.
Alastair Scott announced some months ago that he would be contesting the selection for the seat.
Others who might have been constrained by loyalty to a sitting MP might seek selection now they know he is retiring.
This is the 10th National MP to announce retirement at or before the election which is very healthy for the party and caucus and a stark contrast to the stale line-up in Labour which has had only one MP announce his intention to retire.