Ministers expect to have to act no more than twice a year to force schools and education authorities to improve their performance.
This revelation, buried in the financial memorandum of the education Bill published this week, will undoubtedly reinforce opposition from sceptics who believe the legislation is taking a hammer to crack a nut.
The Scottish Executive confirmed this week that it is pressing ahead with plans for legislation to intervene where authorities and schools fail to take action to improve their performance - despite opposition from most of the authorities.
The School Education (Ministerial Powers and Independent Schools) (Scotland) Bill was published along with an evaluation by the Executive of the 49 responses received during the consultation period. The analysis showed deep and continuing hostility to the legislation, with critics arguing that ministers have sufficient powers and that there is no evidence authorities and schools fail to act following critical inspection reports.
The most recent example was last week's publication of an HMI report on Braeview Academy in Dundee, which received a record 10 unsatisfactory grades and began efforts to sort itself out before the verdict hit the streets.
Ministers are at pains to stress the "last resort" nature of the legislation and argue that existing powers of intervention are not specific enough. They also make clear that they will only intervene if HMI asks them to do so. But that, too, is controversial.
While most of those who responded agreed it was important that referrals to ministers should be "by those who have an in-depth knowledge of educational issues", others feared HMI could face a conflict of roles. Its impartiality and its role in supporting schools could be compromised if it was also recommending intervention, it was argued.
There was also "unease" at the fact that HMI would end up referring a school or authority and then assessing any action - ironically the very "judge and jury" criticism that led to the inspectorate being removed from an overt policy-making role.
A further twist emerged in comments that called for recommendations on intervention not to be restricted to inspectors, given the length of time between HMI visits. The rights of parents and others to refer struggling schools was emphasised.
The Executive's memorandum accompanying the Bill rejects the arguments that existing legislation is sufficient. In particular, the much-cited section 70 of the 1980 Education Act only applies where an authority or school is in specific breach of a statutory duty.
And the 2000 Standards in Scotland's Schools etc Act, while it placed a new duty on ministers to endeavour to secure improvements in schools, does not give them powers to secure improvement where authorities have not taken sufficient steps to do so.
"While such circumstances are considered likely to be rare," the memorandum states, "ministers need such powers in order that they can meet their duty to secure improvement if required."
The application of the Bill to independent schools has been welcomed. The intention is that "no school escapes appropriate scrutiny" which means the definition of an independent school as having five or more pupils will be removed. The Bill also toughens up the policing regime for the independent sector, allowing ministers to act immediately if there is concern about the care and welfare of pupils.
Inspectors have in the past two years heavily criticised Cademuir International School in Dumfries and Galloway and Iqra Academy, the Islamic primary in Glasgow, which is now closed. The latter case heavily influenced ministers.
According to the official figures, the new measures will come at marginal cost - a total of just over pound;14,000 for action involving schools and authorities, and an eventual pound;6,000 a year to deal with the new powers over independent schools.
Costs for HMI, the financial memorandum states, are based on "the assumption that each power (for schools and authorities) would be used once a year".