However, Key is anxious to avoid being seen as too heavy-handed.
"It's not something we want to do in a way that is seen as being punitive," he said. "We are really trying to make positive change here."
The objective, he said, was to have fewer people on benefits and to treat those on a benefit better.
It might cost more up front but it would pay off in the long run.
Today's focus on youth is the Government's first response to the welfare working group, chaired by Paula Rebstock.
The group recommended any young person aged 16 or 17 and receiving a benefit should be fully engaged in education, training or paid work or a combination. It also said they should be required to live with a responsible adult and the benefit paid to the adult. Sole parents aged 16 and 17 should have to undertake parenting and budgeting courses.
Meanwhile, Finance Minister Bill English encountered some flak from the conference floor over the proposed sale of up to a 49 per cent share of selected state-owned assets.
He said New Zealand "mums and dads" would be first in the queue in the share floats if National led the next Government. But he could not guarantee that they would not on-sell it to foreigners, because without the freedom to sell the shares there wouldn't be an operating market.
Party president Peter Goodfellow said membership had grown by 8 per cent last year and he wanted it to increase by another 15 per cent this year.
Row flares over Bennett benefit letter
Frustrated about your taxes going to people on benefits?
Don't worry - Social Development Minister Paula Bennett knows how you feel.
In a letter to a Waikato man this week, she wrote: "I know many people are frustrated that they and their colleagues and family work hard to support themselves while people on benefits receive state assistance."
Green Party co-leader Metiria Turei accused Bennett of "a complete lack of compassion".
In Turei's view, the letter appeared devoid of understanding as to the reasons people needed state support. She said Bennett had also avoided taking responsibility for any impact government policies had on creating unemployment.
She said it conveyed the impression Bennett sided with those who were "frustrated".
Bennett did not return calls.