As Labour ministers in England and Scotland make their plans clear, the British Youth Council said they should consult under-18s on the issue. It has pledged to carry out its own consultation.
Jenny Commin, a 21-year-old spokesperson for the council, said: "Young people's voices are missing from the Government's proposals. They should be involved in decisions that affect their lives and we will be consulting widely to gain their views."
The council has also criticised proposals to fine people who refuse to stay in education or training until they are 18.
Ms Commin said: "Since the majority of young people choose to stay in education past 16 anyway, the ones least likely to participate voluntarily are those that the proposals are supposedly designed to help. It is unlikely that the threat of a fine will encourage them to participate if they don't want to, and any Asbo-style attendance orders will have the consequence of further stigmatising the very young people the Govern-ment is trying to help."
The British Youth Council represents more than 170 national youth organisations and works to ensure young people are involved at every level of decision-making to allow them to be represented and to make their voices heard.
Plans to increase the leaving age throughout the UK have been laid out by Chancellor Gordon Brown and Scotland's First Minister Jack McConnell. It would come into effect in 2013 in England, but there is no timescale for Scotland and the plan only has the status at present of being part of the Labour Party's election manifesto.
Ministers believe that a 17 year-old choosing to stay out of work or education should be as unacceptable as a 14-year-old skipping lessons in school. All teenagers under-19 would have to be working towards an "accredited qualification" or be in work or volunteering.
The proposals have raised concerns among the educational establishment. The Educational Institute of Scotland and the National Union of Teachers oppose compelling young people to stay on in education until 18.
Compulsion has also been opposed by the National Union of Students and the University and College Union south of the border.
As well as opposing the principle of compulsion, the universities and colleges question whether there will be sufficient resources to take on the influx of students which would result.