One Nation gave three different migration numbers in two days. Then Hanson deleted the old posts.

One Nation has had three migration numbers in 48 hours.

David Farley, the party's member for Farrer, told ABC's Insiders on Sunday that the 130,000 net overseas migration target does not include Pacific labour scheme workers, aged-care nurses or other in-demand skilled workers.

"If you take the PALM program in itself, that's about 40,000 a year," Mr Farley said. "You take the skilled aged care nurses, probably 68 to 70,000 a year."

Add those back and the real number is about 230,000.

Labor's Treasury forecast for 2027-28 is 225,000.

Pauline Hanson posted within hours that the policy is 130,000, and less than half Labor's current level.

Barnaby Joyce was sent out on Monday to call it a rookie mistake.

"Show me a political career where people haven't made a mistake and I'll show you a person who's not told the truth," Mr Joyce told Sunrise.

Then Senator Hanson deleted her old posts on the subject.

Here is the problem with the rookie defence.

Mr Farley ran the Australian Agricultural Company as managing director and chief executive from December 2009 to July 2013.

During that time he backed bringing Indian workers to Australia on 457 and 417 visas to staff a new Darwin abattoir that would create 260 jobs.

In the same period he accused Mr Joyce of xenophobia for opposing Chinese investment in Australian farmland.

He was counselled by Senator Hanson during the byelection campaign after agreeing that a net migration figure of 306,000 was probably not too many.

George Christensen, who campaigned with him in Farrer, said on Tuesday he had warned Mr Farley more than once to shut up about immigration, and that Senator Hanson had said the same privately.

A man who spent his career importing farm labour is not confused about migration.

He is the only one in the party who has had to make the numbers work.

On the technical question he is also closer to right than his leader.

Senator Hanson's defence was that short-term seasonal workers who fail the residency test are not counted in net overseas migration.

That holds for the nine-month placements.

Pacific workers on placements of one to four years are counted, and so are backpackers who stay longer than a year.

The bill has already arrived.

The DemosAU poll published Monday has One Nation on 24 per cent, down five points in a month, behind Labor on 26 and the Coalition on 25.

In June the party was on 30.

Nobody else has a policy either.

Home Affairs Minister Tony Burke pulled out of a Press Club address on Labor's migration plan at the last minute, and Coalition home affairs spokesman Jonathon Duniam says his side will not release its numbers this year.

The difference is that migration is the one thing One Nation has been selling for 30 years.

It is now the thing three of its MPs cannot describe the same way twice.