Headteachers have claimed it is unfair for "outstanding" schools that have gone unchecked for five years or more to face full Ofsted inspections in which they could be downgraded.
The Association of School and College Leaders (ASCL) has questioned the way in which the government is planning to end the exemption on "outstanding" schools facing routine inspection by Ofsted.
The Department for Education is consulting on plans that would mean schools were subject to full inspections if they had not been inspected for five years or more.
Education secretary: 'Outstanding' schools' exemption will be lifted
"Outstanding"-rated schools checked by the watchdog since September 2015 would receive a section 8 inspection that would not result in a change of rating.
This is in line with how Ofsted currently inspects "good" schools.
ASCL said it supported "outstanding" schools being routinely inspected, but the way the government was planning to do this would be unfair to approximately 2,900 schools and colleges that would face full inspection.
The union said it was not the fault of schools if they had gone more than five years without an Ofsted check and they should not be treated more harshly as a result.
Stephen Rollett, the union’s curriculum and inspection specialist, said: “The government is arguing that 'outstanding' schools and colleges last inspected before September 2015 should have full inspections because they have gone longer without one. But it is an artificial distinction.
“Ofsted already has a system for monitoring results and sending in an inspection team if standards are felt to be at risk, and this applies equally to all schools and colleges rated as 'outstanding' regardless of when they were last inspected. There is no need to now subject some of them to a greater degree of scrutiny than others.
“We have argued very strongly for a more proportionate inspection system which supports schools and colleges to retain their rating rather than acting as a cliff edge, and this is what lighter-touch inspections are supposed to achieve.
"It is wrong to arbitrarily abandon this approach for many of those which are rated as 'outstanding'. It is not their fault that the government exempted them from inspections and they should not now be treated more harshly.
“This is all about what is best for students and parents, and it is hard to see how they would be helped by an inconsistent approach to inspection which means their school or college could suddenly lose its 'outstanding' rating without it being given any opportunity to address issues identified by inspectors.”
Ofsted data on inspections of 'outstanding'-rated schools and colleges, shows that 2,833 primary and secondary schools, and 37 colleges and 16-19 academies, received their last full inspection before September 2015.
Ofsted has inspected 710 'outstanding'-rated schools since then.
The DfE announced earlier this year that it was planning to end the exemption on 'outstanding' schools being routinely reinspected by Ofsted.
It plans for all 'outstanding' schools to be inspected by Ofsted within five years.
The DfE has been contacted for comment.