National is set to make a crackdown on welfare and long-term beneficiaries a central part of its election campaign with reforms John Key says will be based on "if you can work, you must work".

The Prime Minister says the Government will forge ahead with some of the Welfare Working Group's recommendations, aimed at pushing 100,000 beneficiaries into work within a decade.

The only recommendation he ruled out immediately yesterday was for solo mothers who had another child while on the benefit to return to work when that child was 14 weeks old.

But he would not rule out setting another age for that to happen - indicating the Government could be considering the group's second option of a return to work when the child was 1.

At present under National's rules, single mothers are not required to look for work until their youngest child is 6.

He said significant reform of the system would be steered by a group of high-ranked ministers and the proposed reforms set out before the election.

The Budget set aside $40 million for the reforms, likely to be the system's largest shakeup since it began in 1938.

Mr Key said the welfare system should send a consistent message that "if you can work, you must work".

That message was not being sent and that was not fair on taxpayers, or on beneficiaries and their children.

"The proportion of the working-age population on benefits has increased from 2 per cent to 13 per cent since 1970.

"I think New Zealanders would take some convincing that that increase is justified," he said.

Auckland Poverty Action Group spokeswoman Sue Bradford said the line-up of high-powered ministers charged with the reforms showed National planned significant change.

"They are clearly going to do a 'beneficiaries and bludgers' dog-whistle campaign. And we will fight them on it the whole way. We have to because we can't afford to have those recommendations in place." She said it amounted to semi-privatisation of the welfare system and would worsen the plight of children who were already struggling.

Mr Key would not discuss individual aspects of the report, but help would be provided to ready people for work and he was prepared to pay extra for that.

Those who genuinely could not work would also continue to get support.

In its February report, the Welfare Working Group made several controversial recommendations, including far more stringent job hunting requirements. It suggested administering benefits through a stand-alone, more business-focused agency rather than Work and Income and in the long-term, contracting the work out to iwi and private organisations.

It also recommended a single benefit with supplements for sickness and invalids beneficiaries and policies such as compulsory contraception.

Labour social development spokeswoman Annette King said National was not creating jobs, but instead punishing beneficiaries for being unable to find jobs that did not exist.

The sticks
* Make most sole parents and the sick/disabled look for work.
* Reduce benefits for most people after one year and/or five years.

The carrots
* More specialist case managers for sole parents, addicts, ex-inmates.
* More help for childcare and after-school care.
* Reform schools to encourage apprenticeships and training.
* By-Maori-for-Maori services.
* Move part-time workers off benefits on to in-work tax credits.
* Longer sick leave to encourage employers to keep workers well.