The Government is being called on to ensure youth can still get support if they fail to take up schemes to get into education, work or training.
Labour and the Greens say some unemployed youth will fall through the cracks under the Government's new policy.
The Government announced a raft of schemes to get youth into training or employment at the weekend but the independent youth benefit will no longer be available.
There were 1750 16 and 17-year-olds receiving that benefit as of June. Last year at the same time there were 1242 and in 2007 there were 1294.
The benefit is for youth who have lost the support of their parents or guardians who are: in secondary education or employment related training, or looking for work; or sick, injured, disabled or pregnant.
One initiative was a $20 million Job Ops programme to give 4000 low-skilled people a wage subsidy of $5000 over six months to get them into jobs.
A business would get $3000 for employing a person up front and then $2000 at the end of the six-month period.
Prime Minister John Key said the measure was short term to deal with the recession and would wrap up by the end of next year.
Young people could go to school, take up training which the Government would pay fees for, or go to work, he said.
"In all of those circumstances why should the state be paying someone the benefit?"
It sent the wrong message to put a young person on a benefit and expectations needed to be set higher, Mr Key said.
Green Party social development spokeswoman Sue Bradford said young people at risk of falling through the cracks needed support.
"The independent youth benefit is available as a payment of last report for 16 and 17-year-olds who have no means of support from their family - usually because of family breakdown - or from employment."
Ms Bradford said the benefit was often the only way such young people could get out of desperate situations without resorting to crime or prostitution.
"It is already very difficult for young people to access the independent youth benefit." Mr Key said that under the scheme when there were exceptional circumstances youth still be able to get the benefit.
Ms Bradford said she wanted to know what he would consider "exceptional circumstances".
Labour's Maryan Street was concerned by the blanket rule and she was worried some youth, for example who had been thrown out of home and had personal problems, would suffer.
"I do have concerns around that ... it looks to me like this policy opens up cracks that young people can fall through."
Sometimes a youth's own rebellious nature made life difficult for them but they still needed help.
"Punishing them by not making any support available and compelling them back into either dysfunctional or unhelpful circumstances is not going to be the answer."
The New Zealand Aotearoa Adolescent Health and Development executive officer Sara Helm welcomed the Jobs Op scheme.
"We are especially pleased that this substantial group of young people will not waste their skills and talent during this recession and instead will be given an opportunity to either study or gain valuable work experience," Ms Helm said.
However, she was also concerned that there would not be support for some.
"They will be hard hit by this change." The schemes announced have largely received positive responses.
Institutes of Technology and Polytechnics executive director Dave Guerin said the sector was in a good position to meet the demand and was experienced at transitional youth from schools into training.
The Tertiary Education Union (TEU) welcomed the expansion of the Youth Guarantee policy to get more 16 and 17 year-olds not engaged in school to study at polytechs and other initiatives.
TEU national secretary Sharn Riggs said the move was a positive step. However polytechs were still struggling to cope with caps as more people sought to study during the recession.
