The Department for Education has been accused of displaying “timidity” and “paralysis” in a sign that it is no longer “pulling the strings” on policy.

Geoff Barton, general secretary of the Association of School and College Leaders (ASCL), has warned that a possible power shift to No 10 has resulted in the DfE taking the “default position” that “more of the same is going to be better”.

Speaking at a fringe event at the Liberal Democrats’ annual conference at the weekend, Mr Barton said he had sent numerous letters to the DfE, “none of which have been answered, in general”.

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Asked if the government realised “the adverse side of the current situation, particularly with regard to the narrowness of the curriculum and the testing regime”, Mr Barton said “they obviously know it’s been a failure this year”, but he hasn’t sensed “any appetite” for more radical thinking.

He said: “First of all, do politicians in the current government recognise the imbalance in what they’ve got - the narrowness of what they’ve got - the fact that those GCSEs and A levels, disastrously, have failed to be regulated?

“I think they obviously know it’s been a failure this year. Will that lead them to start thinking more broadly, more optimistically - even with the size of the majority they’ve got, could they not be thinking more radically? I don’t get any appetite for that.”

He added: “I think you’ve got a kind of paralysis and a timidity in the department at the moment. And Paul [Whiteman, NAHT school leaders’ union general secretary] and I have written so many letters with other people, none of which have been answered, in general.

“Which shows, I think, that the default position is: ‘more of the same is going to be better’. So my first point is, there’s no sense from the department, I think, that we’re going to be able to improve education by doing anything different.

“And that might be a sign that the department actually isn’t pulling the strings now - that it might be that the real power shift has moved to No 10.”

The prime minister has surrounded himself with advisers with backgrounds in education policy, including Dominic Cummings.

In July, Tes revealed that an adviser who had worked as Nick Gibb’s teacher in residence at the DfE was set to become the head of education in the Downing Street policy unit.

The DfE has been approached for comment.