The Prime Minister says he would not support either of the ACT MPs Roger Douglas or Hilary Calvert as ministers in his executive. But he says he would be happy for any of the party's other three MPs to serve.
The new ACT leader, Don Brash, who is not an MP, will meet the Prime Minister on Tuesday to discuss whether or not the former leader Rodney Hide and the deputy leader, John Boscawen, should retain their ministerial positions.
Mr Key says ministers serve at the pleasure of the Prime Minister but that he will be listening to the opinions of Dr Brash as ACT party leader.
Mr Key says he could support Mr Hide, Mr Boscawen, or the former deputy, Heather Roy, as ministers.
And he says he could accept Ms Roy taking over from Mr Hide as Local Government Minister.
Mr Key says he sees no problem in someone who is not a Member of Parliament dictating who should hold ministerial warrants.
Labour leader Phil Goff says it is curious that Dr Brash, who is not an elected MP, could be in the position of determining whether Mr Hide remains a government minister.
He says it will be a test of how much influence Dr Brash will have over Mr Key in the coming month, and if they were to be elected, as a coalition partner.