A Labour policy to pay the unemployment benefit to laid off workers even if their partners are on high incomes was likely to include a cap, leader Phil Goff said today.

National has been making mileage out of the idea saying Labour would give benefits to millionaires.

Mr Goff said that was not the case and it was targeted at "ordinary low and middle income New Zealanders".

Under media questioning yesterday Mr Goff would not say if there would be a cap on the partner's income but today told Radio New Zealand; "yeah probably there will be a cap".

However he said that was a side issue.

At present, anyone with a partner earning more than $534 a week cannot get even a partial benefit.

"The important point about the policy is that people who are at the hard end of the recession at the moment, who are suffering trauma and who aren't eligible for assistance ought to be."

Prime Minister John Key has ruled out the idea saying it could cost as much as $1 billion over three years.