The Prime Minister says support for the partial asset sales legislation remains solid, and he is very confident the bill will be passed into law.
The bill passed its first reading in Parliament on Thursday by 61 votes to 60, with National's suppport parties, ACT and United Future providing the necessary votes to get it through its first hurdle.
When law, it will allow the Government to sell up to 49% of state-owned Genesis Energy, Meridian Energy, Mighty River Power and Solid Energy.
Opposition MPs called on United Future leader Peter Dunne to heed public opinion and vote down the legislation.
But Mr Dunne says he made it clear before the election he intended to support the sales programme, and will not renege on his deal with National.
Mr Key says ACT and United Future are solid in their support, as are all members of the National Party caucus.
"That's not to say that we don't need do a very good job of continuing to explain our position, and continuing to make sure that we do a good job of honouring the commitments we made.
"But I'm very confident the programme will continue and I'm very confident legislation will be passed."
The bill will be considered by the Finance and Expenditure Select Committee which must report back to Parliament by 16 July.