Australian governments haven't spent enough time arguing for foreign investment in farmland, former trade and investment minister Andrew Robb says, adding our quality of life depends on foreign funds. 
Mr Robb said politicians needed to extend the case for foreign investment beyond the odd speech after an election where the vote for independents and minor parties opposing "selling off the farm" shot up.
"It's not just a speech here, a speech there. It is a constant narrative that you've got to put out there. You've got to get in and debate the people who have a different view," Mr Robb told The Australian Financial Review.
He also said the last election did not show that the electorate had rejected free trade. "I don't think the federal election in fact had anything to do with trade, it didn't feature," he said.
Mr Robb said the debate over the China Free Trade Agreement was a major test, and since it passed and did not become an election issue, the government had succeeded. On the other hand, he said foreign investment had become politicised.
"We've been selling land to foreigners for 200 years. This has been our history and the thing is that governments haven't spent the time," he said.
Mr Robb said Australians' quality of life hinged on foreign investment.
"There is no alternative at the present time. We've got thin capital markets so it is absolutely critical that governments of all persuasions and at all levels carry the narrative about the significance of [foreign investment].
"We have benefited unbelievably, our quality of life is very much a function of sensible foreign investment and we need to carry that argument to the population," he said. Mr Robb said governments needed to communicate that Australian investors were not putting enough of their funds into farmland, which was needed for critical infrastructure and capital works in regional areas and also said foreign investment allowed elderly Australians to leave the land "with dignity".
After the Nationals bolstered their numbers in the recent poll, the Liberals indicated they would not be pulling back from new scrutiny advocated by their Coalition partners despite questions over the economic impact.
Treasurer Scott Morrison rejected advice last week from the Productivity Commission advising the government to dump the Nationals' policies of tighter foreign investment thresholds.
Mr Robb defended the Australian government's decision to rule against some sales on national interest grounds, one of which - the Kidman sale - was lambasted by Country Liberal NT Chief Minister as showing the scheme lacked consistency.
"National interest might mean it causes a level of political opposition mainly perhaps because people don't understand what the benefits are," Mr Robb said.