Gambling a priority if hung parliament

Action to curb problem gambling could get a second guernsey if Australians elect another hung parliament.

Former prime minister Julia Gillard in 2010 promised Tasmanian independent MP Andrew Wilkie substantial poker machine reform in exchange for his support, before reneging two years later after a backlash from the gaming industry.

Independent senator Nick Xenophon said anti-gambling policies would influence his decision on which party to back to form government, if he's able to get a candidate elected to the lower house and they shared the balance of power.

His candidate, Rebecca Sharkey, in the South Australian seat of Mayo is polling well against embattled Liberal MP Jamie Briggs.

Senator Xenophon told ABC TV other key issues would include improving government transparency measures and promoting Australian-made products in government procurement.

Australian Greens leader Richard Di Natale ruled out supporting the coalition to form government, saying it was an inconceivable prospect.

"This government has been a disaster," he told ABC TV on Monday night.

"If the choice came down to who we'd support, we'd like to enter a productive, responsible negotiation with the Labor Party."

Labor MP Terri Butler insisted her party would win a majority in the lower house outright.