The education secretary Nicky Morgan was repeatedly heckled by a hostile audience of head teachers at their national conference in Birmingham this morning. She was met with complete silence when she walked on stage during the National Association of Head Teachers conference, and her speech was met by groans and cries of "rubbish" and "you're not listening".

Morgan is facing a growing backlash from the public, local councils, teachers and MPs against her plans to turn all state schools in England into academies by 2022. Labour opposes Morgan's scheme, which would mean schools would be only accountable to the Department for Education and academy chains, rather than local authorities. Even some Conservative MPs and councillors have spoken out against it.

The leader of the NAHT, Kim Johnson, who accompanied Morgan on stage, has described the benefits of the scheme as "uncertain". Others have expressed concerns over how the scheme will be funded.

"Academies make it easier to spread the reach of the best leaders across several schools," said Morgan, to a frosty reception.

Russell Hobby, who is general secretary of the NAHT, said many of his members were concerned by the DfE's academisation plans.

"They've [schools] had the chance to convert to academy status for five years or more – they've got good reasons for not doing so," he said. "A government that talks about professional autonomy and delegating the control to the front line really needs to listen to that.

"What they want to do is focus on teaching and learning in the classroom, not on all the logistics admin and legal changes that would just be a distraction for them."

Education Secretary Nicky Morgan heckled by teachers as she announces plans to convert schools to academies IBTimes UK

Morgan also apologised to heads for last week's leak of the new SAT spelling exams, which were published on a DfE website just before half a million seven-year-olds had been due to sit them.

There was also time for a fresh sexism row, after one head teacher asked during a Q&A whether schools minister Nick Gibb was running the DfE in place of his boss. Morgan said she was "not going to dignify that sexist remark with a comment".