If a migrant worker has lost their job they should consider going home because Kiwi taxpayers can't afford to support them, says Foreign Affairs Minister Winston Peters.

The Deputy Prime Minister said today the Government told foreigners at the start of the Covid-19 crisis that if their circumstances had changed dramatically, they should go home

"And 50,000 did," Peters said.

According to official advice to Cabinet released in Friday's document dump, there's potentially 380,000 foreigners and migrant workers in New Zealand.

The advice said "repatriation of foreign nationals at such a scale is unlikely to be possible" and they would have to shelter in place in New Zealand.

Peters said Civil Defence had "done their best" to help them out.

"But that said, if you're here with no long-term legal authority or right to be here then perhaps you should go home."

Peters said he would consider helping migrants pay to go home because it would cost "a whole lot less than having them here year after year" supported by the New Zealand taxpayer.

"How many people do you think a population of just under five million could support in this crisis?

"When your destiny was in your own hands and you chose not to take that pathway, what do you think obligations are of the New Zealand people?"

Asked whether the migrant workers were in New Zealand because we'd invited them here to work, Peters said: "Well actually they came of their own volition, we did not move them compulsorily."

Community Law chief executive Sue Moroney is calling on the Government to use the Social Security Act to grant temporary emergency benefits to migrant workers.

The benefits would only be available as long as the Epidemic Notice was in place and would help thousands of people now without work through "no fault of their own", Moroney said.

"When that's lifted, then that's the time that they'll be able to make their way safely home."

Peters had assumed the Government would continue to support migrant workers beyond the crisis, Moroney said.

"That's just not a humane response to expect people trapped here to have no income."

Moroney warned there was a "humanitarian crisis" looming but the Government didn't know the scale of the problem because they didn't have data on how many migrant workers were without work and not on the wage subsidy scheme.

Prime Minister Jacinda Ardern was asked by media today about a Newsroom report that a family received two cans of baked beans, two spaghetti tins, onions, potatoes, canned chickpeas and rice, flour, and sugar in small ziplock bags and told to make it last two weeks.

It lasted the woman's family of seven one day.

Ardern said their experience didn't meet her expectations of the service.

She understood a team on the ground was attempting to contact that woman as her treatment also didn't meet their expectations.

The Government has put $27 million into supporting NGOs and community services and another $30 million to bolster the food and welfare assistance by local authorities and Civil Defence Emergency Management Groups.

Ardern said when someone applied to work in New Zealand they needed to provide evidence they could support themselves if needed, but the Covid-19 situation was extraordinary which was why the additional services had been beefed up.

But she didn't say whether the Government would consider allowing them to access a benefit under the Social Security Act.

On Monday, she denied New Zealand First was blocking benefits for jobless people without residency.

The Government is seeking to temporarily amend immigration law to make it more flexible in the wake of Covid-19.

The Immigration (Covid-19 Response) Amendment Bill had its first reading last week and if passed would allow powers to:

• Impose, vary or cancel conditions for classes of temporary-entry visa holders
• Vary or cancel conditions for classes of resident-class visa holders
• Extend the expiry dates of visas for classes of people
• Grant visas to individuals and classes of people in the absence of an application
• Waive any regulatory requirements for certain classes of application
• Waive the requirement to obtain a transit visa
• Suspend the ability to make applications for visas or submit expressions of interest in applying for visas by classes of people
• Revoke the entry permission of people who arrive either on private aircraft or marine vessels (to align them with people who arrive on commercial flights, who can already be refused entry)

The Epidemic Response Committee heard submissions from immigration experts and employers of migrant workers on the bill last week.

Submitters were broadly supportive of the bill but most wanted to see additional safeguards to ensure migrant workers weren't deprived of their rights.