National's leader and incoming prime minister has the essential agreements he needs to satisfy Governor-General Anand Satyanand he controls a majority in Parliament.
ACT, with five seats, and United Future leader Peter Dunne, his party's sole MP, have pledged support on confidence votes.
With National's 59 seats, Mr Key has a confirmed 64 confidence votes in the 122-member Parliament.
Details of the agreements will be finalised in the next two days.
Mr Key is offering Mr Hide and Mr Dunne ministerial positions outside cabinet, the same minor party arrangement Labour leader Helen Clark set up after the 2005 election with New Zealand First and United Future.
Mr Key wants the Maori Party on board as well, and yesterday he opened negotiations with co-leaders Pita Sharples and Tariana Turia.
After the meeting they indicated they were seriously considering ministerial positions, also outside cabinet, in return for supporting a National-led government.
"It's a whole range of issues, it deals with our policies as well as the possibility of being involved in government...clearly we want to look for some advances for Maori and that's what it's been about," Dr Sharples told reporters.
The Maori Party wants to consult its supporters before agreeing to anything, and it might not make next Wednesday's deadline for ministers to be sworn in.
That would not affect the final deal because Mr Key could hold positions open until Dr Sharples and Mrs Turia are ready.
One of the reasons for the fast track formation of the new government is that Mr Key wants to go to Peru for next weekend's Apec summit meeting.
To do that he has to leave on Thursday and yesterday he said it was highly likely he would be able to.
The leaders of all the world's powerful economies will be at the summit and Mr Key thinks the discussions will be a crucial to finding solutions to the international financial and economic crisis.
