NICKY MORGAN, the education secretary, was billed as a steady hand when she took office in 2014. Her predecessor, Michael Gove, had enraged teachers and their unions (which he christened the “blob”, after a monster from a 1958 science-fiction film) with his shake-up of the education system. By the end of his four years in office there were around 4,000 academies, state-funded schools that are mostly free from government control, nearly 20 times the number at the start of his stint. It was expected that the pace of change would slow under Ms Morgan.

Instead, she has proposed what some reckon to be the most radical reform of school governance in decades. Under plans outlined on March 17th, all schools would become academies by 2022, giving them the freedom to decide their own curriculum, pay teachers what they want and set shorter holidays. It would be a big, rapid change: currently 59% of secondary schools and only 17% of primary schools are academies.

And the proposals are more than just an extension of existing policy. There has been a distinct change of tone from the Gove era, says Jonathan Clifton of the Institute for Public Policy Research, a think-tank. Whereas Mr Gove sought to release schools from the constraints of local authority control before leaving them free to flourish or flounder, Ms Morgan is pushing education in the direction of a more closely managed system.

Under her plans, schools (particularly those in struggling areas) would get more hand-holding from officials. And the government expects that the “vast majority” will join “multi-academy trusts”, charitable bodies which run chains of schools. It wants to encourage such chains on the basis that they allow the most successful managers to run more schools and enable good practice to spread. Chains often have far greater control over their schools than do local authorities, many with distinct cultures, brands and teaching methods. Some, for instance, focus on pupils in deprived areas; others seek to spread a religious ethos. The government plans to introduce league tables to rank chains.

Supporters of the reforms argue that running a dual system, made up of both academies and local-authority schools, is expensive and confusing. But so far there is little evidence to suggest that chains are more adept than local authorities at supervising schools. Last year a report by the Sutton Trust, an education charity, found a wide range of performance in existing chains—and that the gap between good and bad ones was growing. It suggested that new chains should not be allowed to expand until they have demonstrated good results.

Many doubt that the government will be able to spur the creation of sufficient numbers of high-performing chains. The impact of the shortage of good chains is likely to be particularly severe among primary schools, which tend to be smaller than secondaries and more reliant on administrative support from local authorities. It may also be tricky in rural areas, where chains have been slower to take off. “Once people accept the government position, the system will respond. But it will be incredibly difficult to make it work,” says the head of one academy chain.

One potential salve, promoted by educationalists on the left and right and hinted at in Ms Morgan’s plans, would be to allow local authorities in effect to form their own chains. This would enable the best authorities to retain a role in the running of the schools, while also taking on schools in other areas. Some London boroughs are thought to be drawing up such plans.

Even if the government gets the technical details right, the reforms will cause a rumpus. Many doubt that the Department for Education will be able to convert around 16,000 schools to academy status in just six years. There are plenty of good academies, and a few good chains. But forcing the expansion of the system at such a pace is unlikely to improve standards—which in turn could undermine the argument for academies in the first place.