Rumours and denials, deals and ultimatums. Welcome to the world of coalition politics where just about everything is up for grabs as political parties jockey for power, influence and seats around the Cabinet table.

With six seats in Parliament, the Greens are just one of a possible cluster of parties that could lend support to a Labour-led coalition - but at what price?

While the Greens are claiming not to have any "bottom lines" they do have a solid wish list, ranging from protecting the environment to a universal student allowance and a hike in the minimum wage.

But they're not the only small party flexing their political muscles.

New Zealand First wants a "golden age" card for senior citizens, which would cost an estimated $600 million a year.

United Future's demands are quite modest - four bottom lines: maintaining the Families Commission, stopping hate speech laws, preventing the decriminalisation of cannabis and refusing to work with a Labour-Greens coalition.

The new kid on the block, the Maori Party, with its four seats, wants a review of foreshore and seabed legislation and a review of all Maori targeted funding.

And Progressives leader Jim Anderton, who will definitely back a Labour-led coalition, has put his hand up to be Minister of Education.

Political commentators say United Future and NZ First's demands are likely to end up on the negotiating table unless special votes change the complexion of the next government.

Political scientist Tim Bale, formerly of Victoria University and now based at Sussex University in England, believes United Future leader Peter Dunne and NZ First leader Winston Peters are the men who hold "an enormous amount of power" in the coalition negotiations.

That's because, unlike the Greens and the Maori Party, Dunne and Peters could also be wooed by the National Party.

In Europe, Bale says coalition negotiations can take longer than a month "so no one should panic if they take time".

"It's a complex situation - far more complicated than Christmas lists, in which each party's demands may well conflict with others and will involve a mass of multi-level trade-offs by all concerned."

Bale expects Labour would want to cut down this complexity by sticking to a minority government, where it only has to bargain over policies rather than Cabinet seats.

There has been speculation that Dunne might seek the Foreign Affairs portfolio as one of his bottom lines.