The creation of a new super-agency merging HMIE and Learning and Teaching Scotland has prompted demands for the inspectorate's quality assurance role to be kept separate from any advisory role on policy.
As we reported last week, the Scottish Education Quality and Improvement Agency was announced by Education Secretary Michael Russell. He expects it to lead the drive to implement Curriculum for Excellence once it is running early next summer.
Unions and political leaders have criticised Mr Russell for failing to consult them, raising doubts over whether he will get the merger approved by Parliament. Labour education spokesman Des McNulty cautioned that if his party is elected in May, it could halt the plan.
"We have not seen any arguments for the benefits of this merger, and the concerns we have are so serious that Labour would not see this as a done deal," he warned.
The Scottish Government this week insisted that the independence of the inspection system would continue under the new agency and that the senior chief inspector of education would continue to be appointed under Royal Warrant. But a spokeswoman said it was still too early to spell out further details of how the two bodies would be brought together in a single executive agency.
Ronnie Smith, general secretary of the Educational Institute of Scotland, said he did not want a return to the days when HMIE combined the roles of inspecting quality while also advising ministers on policy.
The establishment of the inspectorate as an arm's length body outside government had split these functions, but there has recently been some "slippage", said Mr Smith. He cited as evidence the role now being played by HMIE in advising ministers on school closures.
He said: "If HMIE merges with LTS, will there be a Chinese wall within the new organisation? Will it simply be a question of bringing together back- office functions? Or will it be a genuinely unified, integrated service bringing together the functions of the two bodies?
"If that is so, it would seem to call into question the concept of a wholly independent inspectorate."
By contrast, LTS is not seen as independent, and could be told by government what to do. So by joining it with HMIE, Mr Smith said Mr Russell was creating a body which would be "sitting in judgment on its own doings".
He described it as "a Leviathan structure" and added: "If you create this infrastructure of a body dealing with curriculum, quality assurance and inspection - pretty much everything to do with what teachers are teaching - you come close to putting in place the means with which you could relatively effortlessly alter the place of schools under the management of local authorities."
Labour's Des McNulty said the nature of the announcement - with staff of LTS and HMIE being given only an hour's notice - had created bad feeling and got the process off to a bad start.
There was little synergy between the two organisations; staff of each came from different backgrounds and training, he said. He, too, warned of the potential for compromising HMIE's independence.
"I had these concerns when HMIE was taken off its normal duties in terms of inspection and sent out to assist for four months with implementing CfE," Mr McNulty said. "These concerns are increased as a result of this precipitate merger."
Liberal Democrat education spokesperson Margaret Smith welcomed the move, however. Her party's education working group had recommended the abolition of LTS and the creation of an enhanced role for HMIE in developing, assessing and disseminating best practice and new ideas, she said.