The Federal Opposition has promised to replace a controversial northern infrastructure fund, and to overhaul Australia's temporary skilled migration system, if it wins the election.

Key points: Labor says it will give billions to Northern Australia for gas projects and tourism

Labor says it will give billions to Northern Australia for gas projects and tourism Mr Shorten is also promising to increase the Temporary Skilled Migration Income Threshold from $53,900 a year to $65,000

Mr Shorten is also promising to increase the Temporary Skilled Migration Income Threshold from $53,900 a year to $65,000 Scott Morrison has promised a re-elected Coalition government would create 250,000 new small and family businesses in five years

Labor leader Bill Shorten described the $5 billion Northern Australia Infrastructure Facility (NAIF), set up in 2015, as an "abject failure" that had not delivered for regional communities.

"Labor will replace the failed NAIF with a new fund that will help build nationally important infrastructure projects like gas pipelines across Queensland and the Northern Territory," Mr Shorten said in a statement.

As part of the changes, up to $1.5 billion would be allocated to gas projects and $1 billion would be set aside for tourism.

Mr Shorten will spend a third full day campaigning in Queensland in the marginal LNP seats of Flynn and Dawson.

He will also pledge changes to the temporary skilled migration system, arguing more needs to be done to protect Australian workers from being undercut.

A Labor government would increase the Temporary Skilled Migration Income Threshold from the current rate of $53,900 to $65,000 per year.

It would also create a public register forcing employers to declare the number of visa holders on their books.

PM pitches to small businesses in SA

Scott Morrison has pledged to help small and family business over the next five years. ( ABC News: Adam Kennedy )

Prime Minister Scott Morrison is making his first visit of the campaign to Adelaide, where he will pledge a $100 million growth fund to help small businesses get access to finance.

"This is for those businesses like a local brewery or restaurant that wants to expand interstate or even overseas, or maybe a family owned construction company wanting to grow so they can meet demand," Mr Morrison said.

"All Bill Shorten and Labor are offering is to make those businesses even smaller with $387 billion in higher taxes."

The Prime Minister also promised a re-elected Coalition government would create 250,000 new small and family businesses across the country over the next five years.

Mr Morrison is expected to visit the seat of Boothby, in Adelaide's southern suburbs, held by Liberal MP Nicolle Flint on a margin of 2.7 per cent.

It is considered to be the only South Australian seat in play between the major parties at this election and was visited by Mr Shorten last week.