Up to 100 school advisers in Birmingham will be forced to prove their worth or lose their jobs under new stricter Government guidelines.
The Government wants to see a greater proportion of existing or recently-serving heads used to help other schools improve their performance.
It is creating a new army of advisers called School Improvement Partners who will be linked to every primary and secondary in the country by 2007.
All 100 of Birmingham's school advisers - sometimes called school-link officers - will have to apply for the new posts to see if they meet the national standard.
Dozens more across the region will also be affected.
The policy is likely to hit hardest among secondary schools, where the Government wants to raise the proportion of serving or recently serving SIPs to three-quarters.
A Department for Education and Skills source, closely involved with the initiative, said: "All SIPs will have to be accredited. That is to make sure the standards across the country are uniformly high.
"There is some good practice out there, but there is also some that isn't as good as we would like.
" We want to take the opportunity to make sure everyone is to the standard of the best. Some may not be able to take on the School Improvement Partner role."
Birmingham City Council, one of 30 authorities piloting using SIPs from September, has already expressed concern at the measures, part of the Government's New Relationship with Schools drive.
Les Lawrence (Con Northfield), cabinet member for education, dubbed the policy an "extension of centralised" control over schools when it was launched earlier this month.
But the city's local education authority last night said its advisers were ready to meet the new challenge.
"We are looking forward to building on the good practice already going on in the city where our schools and advisers work together to raise standards," a spokeswoman said.
The Government believes existing or recently serving heads will bring greater "credibility" to the role.
Others, however, claim they will not be as effective as traditional advisers who are not so tied down by having to also run their own school.
John Chowcat, general secretary of the National Association of Educational Inspectors Advisers and Consultants, said: "The problem is even the very best school only represents one model of how to work effectively to raise pupil attainment.
"You need the type of expert that can deal with a range of models and say what is best."
The Government wants to guarantee schools at least three days, and possibly up to 20 days, of contact time with their SIP.
But Mr Chowcat predicted it might find it difficult to recruit heads to the new role.
"There is a strong belief the Government won't get as many serving heads as they think," he said.
Mr Chowcat added school advisers who did not have the day-to-day responsibility of running a school were able to see the bigger picture.
"The idea of serving head teachers playing a role has only limited value," he said. "One of the problems is schools are very stretched with resources and staff. The knowledge you need to be on top of to advise schools is tremendous. So to have people who are specially employed to keep on top of that helping head teachers makes sense."
About 500 SIPs will start working with secondary schools in 30 LEAs next year. A further 40 LEAs will have SIPs linked to primary schools by September 2006.