Local authorities that have failed to finalise plans for transforming post-16 education have received warnings from the Assembly government to complete the work.

Councils have been told by education minister Leighton Andrews that they risk having the process taken away from them if they do not agree “appropriate plans” quickly.

In a public letter responding to concerns about the ambitious transformation agenda, Mr Andrews said some providers were not making sufficient progress.

“My officials continue to invest a considerable amount of time working with these stakeholders, challenging them to develop effective plans for change,” he wrote. “We are, however, reaching a stage where consideration and debate must end and decisions must be made for the sake of all learners.”

All 22 of Wales’s local authorities, along with further education colleges and private training providers, are in the process of overhauling post-16 education provision. They have been asked to plan together to improve education and skill levels while getting the best value for money.

Mr Andrews said all local authorities should have “sensible and sustainable” plans in place to deal with the likely overall reduction in funding expected in 2011-12 that protect frontline services.

Around 70 per cent of transformation proposals are set to be implemented by September, exceeding the government’s original target of 60 per cent.

But a number of local authorities are causing serious concern, and have been told by the minister to get their acts together.

Mr Andrews said that so far the government had not interfered in the process, but warned: “We are prepared to do this if stakeholders fail to agree appropriate plans for improving learning opportunities.”

Dr Philip Dixon, director of the Association of Teachers and Lecturers Cymru, said: “This is the clearest indication yet that the minister is losing patience with certain authorities that are dragging their heels over transformation.”

A spokeswoman for the Welsh Local Government Association said local authorities “fully support” the agenda, but added: “Sometimes transformation is more difficult than people think.

“Local authorities are doing everything they can to make sure their plans are moving along, but there will be challenges. For example, there’s still a lack of clarity over capital funding. We don’t want to get to the situation where the minister has to intervene.”

The minister was responding to a letter from the cross-party Enterprise and Learning Committee, which has been scrutinising the policy.

The committee has heard a number of significant concerns from teaching unions and others about the way the plans are being implemented and delivered.

As well as the impact on jobs and funding, it is worried about a lack of consultation and low morale among school staff.

Mr Andrews said that it was up to schools, colleges and local authorities to consult with trade unions and teachers about workforce changes, not the government.

Dr Dixon called this a “complete cop-out”. He said: “The government is ducking responsibility - on the one hand it wants transformation, but then it is saying it is not responsible for the turbulence in the system.”

The Enterprise and Learning Committee will continue its inquiry in the autumn.

• Original headline: The time for talk on post-16 shake-up is over, minister warns stragglers