Low and middle income earners are the targets of National's two-year long plan to help workers who lose their jobs in the recession.
The additional help National is proposing would be available only to people who are eligible for Working for Families or the existing accommodation supplement.
A National government would give people who lose their jobs in the recession up to $100 a week extra accommodation support.
Those who meet the criteria would also continue to receive the equivalent of the in-work tax credit despite losing their jobs.
The extra support would be available for up to 16 weeks, for those who have been in the same job for six months.
"For the next two years, while New Zealand navigates its way through the global recession, National will offer extra assistance to Kiwis who are hard hit by redundancy," Mr Key told the Waikato Chamber of Commerce on Friday .
"National's transitional relief package will offer assistance to people who are made redundant and who, as a result, either go on a benefit or have to rely on the income of a relatively lowly-paid partner or spouse."
Mr Key said he also expected the country's trading banks to show flexibility towards people who are struggling to meet their obligations in the face of tough economic circumstances.
He said that in the light of the Government's bank deposit guarantee, banks should show compassion to struggling New Zealanders.
Mr Key said National has no right of veto and cannot stop banks foreclosing on mortgages, but is confident banks will act responsibly.
Figures wrong - Clark
Labour leader Helen Clark says National has vastly overstated the value of its package to help those who lose their job in the recession.
Miss Clark said the party does not seem to have taken into account people's eligibility for temporary additional support, or what used to be called the special benefit.
She said that means National's calculations on how much more people would receive under its scheme than Labour's are vastly overstated.
On Thursday, Labour pledged a 13-week job search allowance for those made redundant after five years in the workforce, which would not be means-tested against a partner's income.
The party said said the new allowance would become a permanent feature of the social security system under a Labour Government.
More would benefit under National - Key
National estimates the proposal could cost $42 million a year, though that would depend on how severe the recession turns out to be.
The package would initially be available for two years, at which time National will decide whether it should continue.
National leader John Key told reporters on Friday that National's scheme is more generous than Labour's plan.
Reaction to major parties' policies
New Zealand First leader Winston Peters says neither Labour nor National policy is moving in the right direction
He said the right approach would be to ensure there is enough liquidity to keep confidence in business and employers, which would stop the blight of unemployment.
National Distribution Union secretary Laila Harre said both National and Labour's proposals contain good ideas, as well as flaws.
She said rather than having one or the other, the two should be combined, as they are similar in size and scope and fill in gaps left by each others' ideas.
"Even if it did mean combining the costs of the two programmes, that is not a high price to pay given the level of dislocation that people are going to experience."
Laila Harre said the problem is urgent enough to warrant legislation being passed even before the next government is formed.
