Serious concerns have been raised about the Assembly government's plans to transform post-16 education, including threats to teachers' jobs and a lack of funding.
The cross-party Enterprise and Learning Committee, which has been scrutinising the policy, has written to education minister Leighton Andrews to seek answers on 14 separate points. As well as the impact on jobs and funding, it is worried about a lack of consultation and low morale among school staff.
All 22 of Wales's local authorities, along with further education colleges and private training providers, are in the process of transforming post-16 education provision.
They have been asked to plan together to improve education and skill levels while getting the best value for money.
But the committee has heard a number of significant concerns from teaching unions and others about the way the plans are being implemented and delivered.
Several committee members said they were "taken aback" at the strength of concern from the unions at a meeting last month, while across Wales opposition to proposals are making headlines.
In his letter to the minister, committee chair Gareth Jones AM said there was "dissatisfaction" among schools at the amount of consultation, which has led to resentment in some areas.
"There appeared to be a general feeling that the pace of change within the education sector over the last ten years has been so fast that it has been difficult to achieve tangible results before consecutive strategies have been adequately aligned and made compatible with one another," he said.
Mr Jones asked what influence the Assembly could bring to bear on all those involved in the so-called "transformation agenda" and whether it could "encourage progress" in those areas where it has been slow.
Funding is also "an issue of some concern", Mr Jones wrote, because of increased transport costs for pupils and staff travelling between school and college sites, and specialist equipment needed for vocational courses.
Despite repeated denials from the Assembly government, the letter reports concerns from teaching unions that the agenda is "subtly pushing" a tertiary approach.
It also raises concerns over the risk of teacher redundancies as a result of structural changes to sixth-forms, the possible loss of experienced teachers and the impact this could have on standards.
Teaching unions welcomed the move and said they looked forward to the minister's response.
The NASUWT said the issues raised presented a "reality check" for the minister and that the proposals should be based on educational merits rather than cost-cutting.
An Assembly government spokeswoman said: "Our transformation policy sets out how we aim to increase learner choice, remove unnecessary duplication of provision and ensure that learning standards are universally excellent.
"The education minster has received a letter from the Enterprise and Learning Committee. He will respond in due course."