Labour is New Zealand's oldest political party - started 100 years ago on July 7, 1916.
Members of its Whanganui branch meet to mark the centenary on Thursday this week, with drinks at 5.30pm in the dining room of the Grand Hotel.
The hotel has been the venue for many a party election meeting. Branch deputy chairman Bob Dempsey said it had "good vibes" for members.
They are asked to bring party memorabilia, such as photographs and news clippings, to the meeting. Contributions could be useful in a history of the branch that is being compiled.
Whanganui has a strong Labour tradition, branch chairman Craig Paynter said. Its branch membership has grown in the last few years, and new members are always welcome.
The Whanganui Electorate also has a Labour Party branch based in Stratford and Eltham.
Whanganui has had four Labour MPs, the most well-known being Russell Marshall. He was in Parliament from 1972-90, was a successful education minister, took a hand in foreign affairs and was New Zealand's High Commissioner in London from 2002-05.
The branch is now in the process of identifying potential candidates for the 2017 election, since previous candidate Hamish McDouall has said he will contest the mayoralty instead.
The Labour Party's most famous leaders have been Michael Joseph Savage, Norman Kirk, David Lange and Helen Clark.
Among its achievements are the 40-hour working week, building thousands of state houses, the 1939 act that created a welfare state with free health care and benefits, the 1975 Treaty of Waitangi Act and the 1987 nuclear-free New Zealand policy.