The ''sisters'' have been doing it, but male MPs have been a bit slower to realise that forging partnerships across the political divide can produce impressive results.

On the surface, Joyce and Xenophon are strange bedfellows.

Joyce, 42, hails from St George a small country town about 500km west of Brisbane. He has risen through the ranks of the National Party, securing his seat at the 2004 election. Before the married father-of-three entered the Senate, Joyce was a farm worker, an accountant, a rural banker and then a self-employed accountant.

Xenophon, 50, is a former lawyer who lives in Adelaide and served in South Australia's Legislative Council, building a political career as an independent running a no-pokies campaign. The single father-of-one was elected as a Senator for South Australia at the last federal election.

But the city lawyer and the country accountant do have some things in common. Both are articulate, usually serving up some of the best quotes. One of Joyce's recent contributions referred to Prime Minister Kevin Rudd's problem with an in-flight meal on the VIP jet. ''The guy's a psycho chook,'' Joyce said. ''Who in their right mind gets on to a plane and because he doesn't get the right colour birdseed has a spack attack?''

Joyce retreated a bit when told he may have offended. ''Generally I never recant ... anything I say, and I have very colourful language, and if certain people get offended, so be it. But in this instance, I do. Because obviously there is no way I want to offend those people who work with handicapped children. Honest to God, it was only when my media staff told me that [the term] actually refers to people being afflicted with, you know, being spastic.''

Xenophon uses similarly colourful language and both men are political purists, seeing the Senate as the states' house first and foremost.

In his maiden speech, Xenophon said, ''A lot of people talk about the power of this senator or that senator, but none of us have any power other than the power entrusted in us by the people, the voters. They give us this power and they can take it away. That is why I do not swear allegiance to a party and that is why I do not owe allegiance to any one ideology. I have got the next six years to get to know everyone here, but if you want the Reader's Digest version of my approach to this job, here it is: I would rather go down fighting than still be standing because I stayed silent.''

Joyce also practises the politics of conviction, even if it proves unpopular or puts him at odds with the party. Reaching across the aisle is good for politics. As displayed in discussions on euthanasia, RU-486 and therapeutic cloning, it improves the debate when politicians take a stance rather than kowtow to the party line.

This point was highlighted by Peter Costello, who was in a successful, if at times dysfunctional, long-term relationship with John Howard. ''You are sent up here, you have got your views, you represent your constituents, you state your view,'' Costello said this week after announcing he was leaving Parliament. ''Let's have a real debate about these things. I always thought the best parliamentary debates were on things like stem cell research and euthanasia because people actually had to take positions and they had to argue them and ... you see the Parliament at its absolute best.''

Danielle Cronin is Political Correspondent.