Nick Clegg has likened the Department for Education under Michael Gove to the parody TV show The Thick of It, saying the former education secretary was known to keep a handwritten list of medieval monarchs that he believed schoolchildren should be required to learn.

Michael Gove was handwriting lists of which medieval kings schoolchildren should learn, according to his recollection Nick Clegg

Speaking on the Liberal Democrat general election campaign bus on Tuesday, Clegg described the situation as “absurd”, and suggested Gove had come to regard the department as his personal fiefdom.

In an unusually personal attack by one coalition minister on another, Clegg said: “I remember when I thought ‘this is just getting absurd’ was when someone explained to me that Michael Gove was personally handwriting lists of which medieval kings British schoolchildren should learn, according to his personal recollection of which kings and queens are important.

“I just thought: ‘This is something out of The Thick of It.’ You have the secretary of state personally instructing the hapless children of this country which medieval kings you want them to learn by rote.”

He said: “I’m afraid this happens in government. I’ve seen this, where … it all slightly goes to [a secretary of state’s] head. They think it’s their personal fiefdom or their personal gift.”

A friend of Gove said: “These comments are as honest as Clegg’s policy on tuition fees. Gove frequently fought against Clegg’s ludicrous whims being imposed on schools.”

Clegg added that, although he was a big supporter of the government’s free schools policy, there had been a “near departmental obsession” under Gove with opening a small number of new schools: “Some of which were being opened in areas where there wasn’t a particular pressure on school places, when the much larger issue of how you properly finance 24,000 schools across the whole school system was much more pressing.”

He added: “What you can’t do – which is what the Conservatives have come up with – is pantomime horse policy, where they say on the one hand we’ll give more money to a tiny number of hand-picked schools, hand-picked by the Conservatives, [while] on the other hand they will cut over £3bn out of the education budget.”

He said the free schools policy would not have been passed if it were not for his party, but there were “a tiny, tiny number of cases” where state schools were crying out for extra investment and the money went instead to open new free schools, even though there was no pressure on places. “That just seems to me to be an irrational use of scarce resources, in effect, for ideological reasons,” said Clegg.

The news that Gove had compiled such a list was communicated to Clegg’s office during the lengthy negotiations surrounding the new curriculum.

A Conservative party spokesman said Clegg’s comments were another example of the Lib Dems’ “pick and mix approach to coalition”. He said: “It’s thanks to Conservative education secretaries that 1,000,000 more pupils are now in good or outstanding schools. Conservative policies have delivered a 71% increase in students taking rigorous academic subjects and ensured 100,000 six-year-olds are reading more confidently.”

Clegg was following up comments he made in an interview with the Economist last week, when he said the Department for Education under the coalition government had suffered from “fruit-cakey policy spasms” and that he would like to see greater Lib Dem influence in the department in any future coalition government of which the party is a member.

“I might want to try and have secretaries of state in a different department,” he said. “But I think the idea that you have a few secretaries of state as a smaller party, but obviously not as many as the larger party, and then you try and have ministers in as many of the other departments as possible – I think that makes sense.”

