One Nation is considering cuts to Australia’s permanent family visa intake as part of a broader plan to reduce migration, MP David Farley has told ABC News.

The party announced on Monday that it wants to reduce temporary migration by 750,000 places over three years. Its proposal includes preventing the families of temporary skilled workers and international students from entering Australia, but it has not yet specified the size of any future permanent migration intake.

Farley said One Nation would “potentially” reduce family reunion visas for skilled migrants. He said the approach would depend on whether Australia could expand infrastructure, including its health and education systems, sufficiently to avoid placing further pressure on the existing population.

He rejected the suggestion that restricting family visas would make Australia less attractive to skilled workers needed to address workforce shortages. Farley said people could work remotely and that international travel made it possible to remain connected across long distances.

Abul Rizvi, a former deputy secretary of the Immigration Department, said it was illegal to cap family visas for Australian citizens and permanent residents. He cited section 87 of the Migration Act, saying the government did not have the legal power to cap visas for partners and dependent children of those groups.

Rizvi said successive governments had nevertheless limited the number of visas issued administratively, resulting in a partner-visa backlog of about 120,000 applications. He said no party had explained how it would address what he described as this illegal practice. The current permanent family visa intake under Labor is 52,460 places a year.

One Nation says it has commissioned extensive economic modelling and will release its full immigration strategy within the next fortnight. Labor frontbencher Murray Watt warned the proposal could create critical workforce shortages, while Liberal deputy leader Jane Hume said it could push the economy into recession. The government has been contacted for comment.