Backpackers and other visitors on working holidays will be able to stay in Australia longer under a federal government plan to help farmers fill job shortages.

Pacific islanders taking up seasonal work will be able to stay three months longer, while the age limit for working holiday visas for some countries will be lifted to 35.

Backpackers will no longer need to leave jobs every six months and will be able to triple the length of their stay if they do extra agricultural work.

The changes come after the Nationals failed to deliver a promised agricultural visa and an attempt to force jobless Australians to pick fruit and tend to animals was dismissed by the industry.

Prime Minister Scott Morrison was visiting a strawberry farm in southeast Queensland to outline the changes.

“Australians filling Australian jobs is my No.1 priority, but when this isn’t possible we need to ensure our farmers aren’t left high and dry with rotting crops, especially in the strawberry industry,” he told The Courier-Mail.

Labor frontbencher Andrew Leigh was sceptical about what he described as a “short-sighted” announcement.

A report published last week found backpackers in Australia, about a third of whom are paid less than $12 an hour, are owed billion dollars in unpaid wages.

“The government needs to be very clear about how it’s going to deal with those abuses and how it’s going to create more opportunities for Australians to work in agricultural work,” Dr Leigh told Sky News.

Deputy Prime Minister and Nationals leader Michael McCormack denied the changes were an admission his party’s push for an agricultural visa was dead in the water.

“It was always going to be difficult to get a specific ag visa in time for this harvest but we are working towards making sure there are more permanent arrangements in place,” Mr McCormack told AAP in Melbourne.

“At the end of the day, what needed to happen was we needed to have the workers on the ground to pick the fruit and pick the crops.

“We will make sure good workers can come again. That’s all farmers want.”

A rule that forced some backpackers to work in northern Australia is also being dumped. They will instead be allowed to work in a far wider range of regions throughout the country.

Australia’s agricultural sector has almost doubled in value into a $63.4 billion industry over the past decade.

Some 419,000 backpackers visited Australia last year, spending 1.4 million nights in regional areas where they spent $920 million.

“Every dollar they earn here, they spend here, that’s the whole point,” Mr Morrison said.

-AAP