The only school in the country that is closed over crumbling concrete fears said it has been given no idea of when it will be allowed to reopen.
All 1,500 students at Stepney All Saints secondary school in Tower Hamlets are now learning from home, despite the school reopening fully after the summer holidays.
A spokesman for the school said nothing has changed since Raac (reinforced autoclaved aerated concrete) was found at the four-storey building over the summer holidays.
Props were put in place to ensure ceilings were safe and it reopened as normal at the beginning of the school term. But after updated guidance was issued by the Department for Education the school was closed down on Thursday.
The spokesman said there are “ongoing meetings” about when the school will reopen, but no plans are in place.
He added: “We put loads of props up on the fourth floor to add further support to the ceiling so there was no immediate risk of it looking like it was going to collapse in. That met the guidance at that point. Nothing changed – it’s not like we suddenly saw massive cracks, it was just the guidance changed.”
He said while remote learning is still a novelty for students, “frustration may come out when we know quite how long we are in this holding pattern for.”
Stepney All Saints was one of 27 new schools named on Tuesday as being affected by Raac, taking the total to 174. It is the only school where all students are working from home.
Ms Keegan made the claim about "high-quality" portable cabins as she updated MPs in the Commons on how the Government is handling the presence of collapse-risk reinforced autoclaved aerated concrete (Raac) in schools.
Nearly 250 temporary classrooms have been ordered by at least 29 schools in response to the Raac crisis - and 11 of those schools already have temporary classrooms in place, the DfE’s top official told MPs on Tuesday.
In response to a question on the provision of temporary classrooms as a result of the Raac crisis, Ms Keegan told the Commons: "I have been to a number of these schools and seen children and met children in the Portakabins, and in fact at the first school I went to the children were all petitioning me to stay in the Portakabin because they actually preferred it to the classroom.
"The Portakabins are very high quality and I would advise her to go and see some of the high-quality Portakabins that we have, and that is true."
Scores of schools and colleges in England were told by the Government to fully or partly close their buildings just days before the start of the autumn term amid concerns about collapse-prone Raac.
The updated DfE list suggests 24 schools are offering some remote learning because Raac was found.
On Tuesday, school system minister Baroness Barran and the DfE’s top official, permanent secretary Susan Acland-Hood, were questioned by MPs on the Education Select Committee.
Ms Acland-Hood could not say how many temporary classrooms, which have been provided by both the department and local responsible bodies, are being used at the affected schools.
But she told the MPs that a total of 248 mobile classrooms have been ordered in response to the situation, as well as toilets - and 11 schools are already operating with temporary classrooms.
Julie McCulloch, director of policy at the Association of School and College Leaders (ASCL), said: "The Education Secretary should be reflecting on why children prefer temporary accommodation. Much of the school estate is outdated and should have been refurbished or rebuilt many years ago."
She added: "Temporary accommodation is just that - temporary. Children should be learning in classrooms which are modern, in good repair and permanent."
Shadow education secretary Bridget Phillipson said the Raac crisis has been a "colossal shambles" as she called on Ms Keegan to take responsibility for "three weeks of chaos".
Paul Whiteman, general secretary of school leaders’ union the NAHT, said: "We still need a real sense of a clear plan, not just to put short-term mitigation measures in place, but to properly repair or replace buildings so they are fit for purpose.
"Propping up ceilings with metal poles is clearly not a serious option in the medium or long term."
He added: "This situation has been brought about by years of neglect and under-investment in the school estate.
"Too many schools have been allowed to fall into a state of disrepair and the current crisis is just one symptom of a problem that has been long in the making."
The DfE said 148 of the 174 education settings confirmed to have collapse-risk concrete are now offering full-time, face-to-face learning to all pupils.
Last year, the DfE issued a questionnaire to responsible bodies for all schools in England to ask them to identify whether they suspected they had Raac.
Responsible bodies have submitted responses to the questionnaire for 98.6 per cent of schools with blocks built in the target era, the DfE has confirmed.
