In politics the idea of the ‘power broker’ is usually associated with men and women who operate deep within political parties, corporations or sectional interest groups, and who seek to influence decision-makers usually behind closed doors. Power broking is usually the domain of factional convenors, union strong-men, corporate heavy-weights, party directors, ‘machine men’ and communications gurus.

In more recent times, however, a new breed of power broker has emerged whose background seems to be free from internecine intrigue, and whose basis for wielding influence harks back to a rather old-fashioned notion of local parish politics.

They are the independent or minor-party based representative who holds the ‘balance of power’ – usually in the upper house but, in recent times, even in the lower house where governments are made or broken.

Interest in the cross-bench power broker is rising as it becomes clear that Tony Abbott becomes the first prime minister since Gough Whitlam to be confronted with a Senate he does not control or with whom he might not be able to deal.

So, who are the real power brokers in Australian politics?

Australia’s most powerful politician is … Christine Milne (for the time being)

Greens leader Christine Milne

The Greens senator from Tasmania who is also party leader. Thanks to section 13 of the Constitution which defers the sitting of a new Senate until 1 July in the year after a general election, Senator Milne’s party currently holds the balance of power in the upper house.

When Labor and the Greens vote together (which they have been doing consistently since the 2013 election), bills can’t get through the parliament and the government can’t address its policy agenda.

That is what’s happening at the moment, and it is causing the frustrated Coalition government to get bogged down in silliness (knighthoods) as it is unable to abolish the carbon tax, the mining tax or reform industrial relations.

Senator Milne and the Greens had a great WA Senate election re-run – a matter of some importance to Milne’s tenure as leader.

Senator Scott Ludlum has been returned.If Green surplus helps Louise Pratt win her seat the collective Labor-Green vote in the new Senate will be 36 (at worst it will be 35).

If the collective left can persuade three other senators to vote with them after July 1, Tony Abbott’s legislative programme will again be blocked.

Australia’s most powerful politician will be … Clive Palmer (after July 1)

Leader of Palmer United Party, Clive Palmer.

Miner, man with deep pockets, runs a political party and the Palmer United Party member for the lower house seat of Fairfax (Queensland).

It all seems a bit odd that a man who is in the lower house can act as a power-broker in the upper house, but these are odd times in right-of-centre politics. With his economic interests Mr Palmer would normally be expected to be aligned with the Liberal and National parties and, indeed, he was a member of the Queensland Nationals.

For most of his political life, however, he has been a spoiler for his own side of politics.

He supported the Joh For PM campaign that cruelled John Howard’s early prime ministerial ambitions, he opposed the Liberal and National merger in Queensland politics and he has been a strident critic of Campbell Newman, the Liberal premier of Queensland.

Palmer threatened to run for parliament and he was as good as his promise. His populist message appeals to a critical mass of voters because it expresses dismay at everything either of the major parties are about without actually saying what he, Palmer, would do if he was in power.

The critical question now is to what extent does Mr Palmer exerts authority and leadership over those who are in the Senate as Palmer United Party senators, plus Ricky Muir from Victoria who belongs to something called the Australian Motoring Enthusiasts Party?

Australia’s most powerful independents will be … Ricky Muir, John Madigan, Nick Xenophon, Bob Day

Australian Motoring Enthusiast Party’s Ricky Muir

Put simply, any one of these guys could be a power broker if the Palmer group vote with Labor and the Greens.

With Muir, this theoretically gives Palmer four votes in the Senate. If these four were to vote with Labor and the Greens on any matter before the upper house, the government’s initiatives would be defeated. This would be the case even if Labor and the Greens could only muster two seats between them in the Western Australian by-election and end up with a total of 35 seats.

Unlike the Palmer group, most of these cross bench senators have policy axes to grind.

Day and Madigan come from socially conservative parties dedicated to fighting the Greens on everything from abortion to same sex marriage, while Nick Xenophon goes on and on about the evils of poker machines.

This group could look to other upper house cross bench MPs for an operational model. In NSW the Shooters and Fishers Party MPs, Robert Brown and Robert Borsak show how to get a major party to accede to your specific policy demands in exchange for passage of bills through the upper house.

If Madigan and Day seek to horse-trade on matters such as abortion and/or stem cell research, they might find a sympathetic prime ministerial ear.

What it all means

On July 1 this collection of cross-bench MPs – and the odd central player from Fairfax in the House of Representatives – have the potential to be new power brokers. The consequences will either be a flurry of socially conservative policies and/or legislative inertia.

One thing seems certain, however, and that is that, whatever happens, Tony Abbott will not want to invoke Section 57 of the constitution and call a double dissolution election for fear of having even more of these players elected to the next national parliament.