Racing Minister Nathan Guy said Mr Tremain was suitable because of his background in racing (he owns racehorses through a syndicate) and as former Internal Affairs Minister responsible for gaming laws.
There is speculation Trade Minister Tim Groser will soon be appointed Ambassador in Washington and that Speaker David Carter will replace Sir Lockwood Smith in London.
Such appointments are often seen as "jobs for the boys" or patronage.
Sometimes it can backfire on a Government. Labour and the Green Party criticised the appointment of Jackie Blue as Equal Opportunities Commissioner.
Since then, Dr Blue has proved to have gumption, taking strong stands that could embarrass the Government on issues including equal pay in the public service, the handling of Roger Sutton over claims of inappropriate behaviour, and the Roast Busters investigation.
National had accused Labour of crony appointments, especially for then party president Mike Williams, who was on several government and SOE boards from 2000-2008.
Labour has complained National is making political appointments to roles in which independence is desirable, such as Katherine Rich's appointment to the Health Promotion Agency.
In the club
The former MPs
Katherine Rich:
Chief executive of Food and Grocery Council. Government appointments include Apec Business Advisory Council (March 2014, appointed by John Key), Health Promotion Agency (2011 and 2012 by Health Ministers). Previous appointments included chairing Agriculture Emissions Trading Scheme Advisory Committee (2010).
Dame Jenny Shipley: Roles include the independent review panel appointed by Canterbury Earthquake Minister Gerry Brownlee to monitor use of emergency legislation. Last December Mr Brownlee also appointed her to chair the "transition advisory board" for Christchurch. Previous appointments include chairing Genesis Power (2009, reappointed 2012).
Jeff Grant: Former National MP and office holder, farmer. Involved in Southland MP Todd Barclay's campaign last year. Appointed to board of AgResearch by Steven Joyce in June 2014. Also council of Southern Institute of Technology in 2013. The former chairman of Meat and Wool New Zealand was also chairman of the Government's Wool Taskforce in 2009.
Georgina te Heuheu: Former National MP, appointed to chair Maori TV in April 2012 (by Pita Sharples).
Jackie Blue: Appointed Equal Opportunities Commissioner last year.
Tau Henare: Appointed in February as Auckland representative on the Rules Reduction Taskforce, charged with cutting red tape (by Paula Bennett).
John Carter: Appointed to the same taskforce as Mr Henare. Is Far North Mayor. Previously appointed High Commissioner to the Cook Islands.
Belinda Vernon: Director at Institute of Geological and Nuclear Sciences.
Gavan Herlihy: Director at LandCare Research.
The National Party office holders
Andrew von Dadelszen: Former Bay of Plenty councillor, longstanding chairman of National's "Blue Greens" environmental group. Wife works for Simon Bridges in Tauranga. Appointments include Environmental Protection Authority in 2013 (by Amy Adams) and Institute for Plant and Food Research in 2014 (by Steven Joyce). Was also appointed to a lotteries distribution committee in 2011.
Glenda Hughes: National Party's Lower North Island regional chairwoman and 2002 candidate. Was appointed to chair the Racing Board in July 2013 by Nathan Guy.
Judy Kirk: Former National Party president, appointed to chair Lotteries Commission in 2009. Reappointed this year. Appointed director of MetService in 2011, reappointed 2014.
Stephen McElrea: Electorate chairman for John Key in Helensville. On the board of NZ on Air.
The donor
Chris Parkin: Owner of Museum Hotel, art collector and large donor to National. Appointed to the Tourism Board by John Key in 2013 and as Te Papa chairman in 2010 by Chris Finlayson.
Others:
Mark Gilbert:</i> Until 2012 was managing director of BMW New Zealand, which provides the ministerial and VIP Crown cars. Appointed to Lotteries Commission this month by Peter Dunne. Was also chairman of the Motorcycle Safety Advisory Council in 2013. Not known if he is a donor: no donations over the $15,000 disclosable limit have been listed from him or BMW.