Greens are strictly off the menu for Peter Dunne.

The United Future leader, whose party has been reduced to three MPs - five fewer than last election - unleashed a vitriolic attack on the Green Party yesterday and reiterated that he would not support a Government in formal coalition with them.

"I think they're dangerous. I think they're Luddites in terms of their transport and energy policies. I think their foreign policy verges on being in favour of terrorism, and they've never yet found a drug they're not in favour of," Mr Dunne said on Newstalk ZB.

But Mr Dunne later said he would tolerate the Greens having a support agreement with a Labour-led Government - a concession that could allow United Future to enter a coalition with Labour or to enter into a support agreement to which the Greens were also party.

It was not just the Greens who were the target for Mr Dunne's pique.

On election night the normally affable MP was incensed when TVOne failed to mention United Future during its introduction to the election coverage and then kept him waiting in the cold outside his Wellington headquarters while it prepared for his arrival.

Mr Dunne hit back by criticising the state broadcaster and its "Auckland stars" during his speech, which was being broadcast live.

Mr Dunne, who was dealing with the loss of five MPs and his party's vote being reduced by almost 4 per cent from the 2002 election, then had two radio interviews that did not go as planned - one because he said the reporter asked "banal" questions, and the other for technical reasons.

Yesterday, Mr Dunne was at pains to explain the bad mood and restore his image as politics' Mr Reasonable.

"I'm not grumpy at all. I'm tired but I'm not grumpy," he insisted.

Mr Dunne's mood appeared to have been improved by phone calls from both Prime Minister Helen Clark and National leader Don Brash yesterday morning and by the possibility he could land a Cabinet role.

Mr Dunne is talking to both leaders, but because Labour polled highest, United Future has agreed it will have the first shot at securing its support.

Mr Dunne said he expected to meet Helen Clark early this week and would also meet Dr Brash, but said that meeting would be of "less significance".

United Future has three policy bottom lines for any negotiations - no change to the Families Commission, no change in the legal status of cannabis and no moves to introduce hate speech laws.

And the party also rules out supporting a Labour-Green coalition.

Mr Dunne said the reason for the stance was not "petulant or personal" but was because the two parties had "significant" policy disagreements.