The licence to teach scheme will fail to benefit education unless the whole school accountability system is "rebalanced", the man responsible for running the initiative has warned.
Keith Bartley, chief executive of the General Teaching Council for England (GTC), said the advantages of the initiative are still unclear and it risks being another layer of bureaucracy that could "stifle" innovation.
His comments come as thousands of teachers continue to protest against the introduction of the licence.
The initiative, due to be introduced from this September, will require teachers to have a licence, renewable every five years, to show that their skills, knowledge and training are up to date.
But speaking at a Westminster Education Forum event in London, Mr Bartley said he was concerned that it would be "unduly burdensome" for teachers and called for a change to the way schools are judged.
"We need assurances that it won't be another layer of accountability in the system," he said. "We are asking the Government what the benefits will be. But there can only be benefits if there is a rebalanced notion of accountability. We've got to implement this, so I've got to tease out the benefits."
A lack of information from the Department for Children, Schools and Families (DCSF) about how the scheme will work means the advantages to teachers are not yet clear, he added.
Ministers have not confirmed whether teachers will get an entitlement to continuing professional development (CPD) to help them meet the criteria of any licence. This has raised concerns because of the varying amounts of money schools spend on training.
Mr Bartley said: "Licensing must add value. It is only worth doing if it brings real and tangible benefits to teaching and learning. It must have enough rigour to make a difference and to enjoy credibility - the last thing we need is a bureaucracy in search of a purpose.
"It should make a distinctive contribution to improvement that cannot be achieved via existing means or at lower cost. It must be fair, it must be proportionate and not unduly burdensome, and the system must not stifle innovation - it should encourage development and improvement."
He expressed particular concern about the impact on part-time and supply staff and those returning to the profession - who get less training - if the licence is introduced.
MPs are debating the system in Parliament, but it is unclear if the proposals will become law before a general election. The Tories have said they would scrap the licence if they win power.
John Bangs, head of education at teaching union the NUT, said it was a "cogs and wheels" approach. About 17,500 members have signed a petition protesting against the licence.
A DCSF spokesman said: "No one wants costly extra red tape and we are clear this will not add to teachers' workloads.
"We are working with the teaching unions on the details of how the licence and entitlement will work and will consult widely with the profession this year."