Reaction continues today to calls by the wealthiest Australian, Gina Rinehart, for a massive increase in defence spending to 5 per cent of gross domestic product (GDP).

The mining mogul made a sudden intervention into the debate over military spending late yesterday at a sunset vigil before Anzac Day outside the Sydney Opera House.

It came after Opposition Leader Peter Dutton pledged this week that if the Coalition won government in next month’s federal election, it would spend an extra $21 billion on strengthening defence – reaching 2.5 per cent of GDP by 2030.

Labor has forecast its defence expenditure to rise from 2.02 per cent of GDP this year to 2.3 per cent by 2034.

Rinehart, speaking at the Channel Seven event yesterday, made the case for much larger spending, but did not say how it would be funded.

She said there was an urgent need for more spending on the Australian Defence Force, especially on high-tech weaponry such as missile defence shields, drones and sea mines.

While Rinehart said she would be speaking further on the issue at a later date, she gave no details about how the country could afford such a big increase in defence spending.

The federal budget would be wrecked by spending 5 per cent of GDP on defence.

Only a few countries, such as Russia and Israel, have defence budgets above that level.

Speaking on Today this morning, Veterans Affairs and Defence Personnel Minister Matt Keogh said he thought it was not appropriate to talk about defence spending on Anzac Day.

“I think getting into the politics of funding in defence is not something that people want to be focused on today.”

But Liberal Senator Dave Sharma said while he didn’t endorse Rinehart’s plan, the spend on defence is going to have to go up.

“It’s clear that the environment around Australia has only made our … neighbourhood less secure and more dangerous. And we need a bigger defence force to match it,” he said.