Secondary headteachers were yesterday expected to put education and lifelong learning minister Jane Davidson on the spot over cash for the Assembly government's reforms of 14-19 learning.
Their concerns follow claims from opposition Assembly members that plans to make the 14-19 curriculum more vocational could fall flat over funding.
Ms Davidson was due to address the Secondary Heads' Association Cymru's annual conference in Llandrindod Wells yesterday, and was expected to face questions about 14-19 policy.
Speaking before the conference, Brian Rowlands, secretary of SHA Cymru, said: "There are concerns that many of these recommendations are still aspirational and lack substance. Funding for collaboration between institutions will need to be specific, guaranteed and sustainable over time."
The government's learning pathways proposals envisage a wider choice of vocational and work-based courses being made available to teenagers, delivered by schools, colleges and trainers working together. Schools and colleges must attract and motivate pupils with timetables honed to their job aspirations as part of the new thinking on 14-19 learning.
Some schools already run apprenticeships and other vocational courses, with pupils spending part of the week out of the classroom on work placements.
And new learning coaches are being trained to help support and motivate those who might otherwise struggle with their work.
Assembly government funding for 14-19 education is presently distributed through 22 networks serving each council area in Wales. A total of more than pound;41 million has been made available from 2006-8 to fund the implementation of learning pathways. In addition, pound;2.9m European funding is available for post-16 education from 2005-7.
Last year (2004-5), each network received pound;50,000, and a further Pounds 140,000 for other pilot developments such as learning coaches and personal support is available this year across the country.
The Assembly government aims to have 220 learning coaches trained by summer 2007, with a training programme due to start early 2006. It says costings will become clearer "when we have seen more from the pilot training programme".
A ministerial report on 14-19, reform written by deputy education minister Christine Chapman and published last month, touched on early concerns about putting the changes in place.
It highlighted differences between schools when introducing the pilot schemes, and suggested there had been too much concentration on disengaged pupils and not enough on those of middle ability.
But it came under fire from opposition Assembly members at last week's education committee.
Janet Ryder, Plaid Cymru's education spokesperson, said there was cross-party support for overhauling 14-19 learning, but added: "It seems we are going head-first into this without the evidence or funding in place to do it."
Ms Chapman told Assembly members the report had been intended as a strategic overview, and that more detailed plans would be published in February.
Initial guidance on 14-19 learning pathways was issued in summer 2004.
Earlier this year, ACCAC, the Welsh qualifications, curriculum and assessment authority, provided specific guidance on delivering the learning core - which includes key and work skills, Welsh-language skills, and personal and social education.
All 14-19 students are expected to receive the core, wherever they study. A recent survey, by teachers' union the NASUWT Cymru, revealed some of its members are unclear about the purpose - or even the existence - of the reforms. More than one-third also said their workload had increased as a result of 14-19 changes.
Geraint Davies, secretary of the NASUWT Cymru, said more debate was needed.
Two Assembly government-organised conferences on 14-19, held in Wrexham last week and Cardiff this week, were not open to the press.
An Assembly spokesperson said: "The deputy minister's report reflects the enthusiasm and commitment throughout Wales for our flagship policy."