Schools across Norfolk and Suffolk are closing their doors today to the bulk of youngsters for what could be months - but some are gearing up to reopen on Monday so the children of key workers can still be taught.

But there was confusion for much of yesterday, with the government having not defined who exactly should be counted as a key worker. Some Norfolk schools were ringing parents to ask what they did for a living.

Many parents are facing the prospect of juggling working from home with helping to educate their children, with schools setting up on-line systems so youngsters get some element of learning as the virus continues to turn normal life upside down.

Prime minister Boris Johnson ordered the closure of schools on Wednesday, but education secretary Gavin Williamson said some would remain open so children of key workers could be taught. However, up to yesterday there was still uncertainty of exactly what the definition of key worker was, although NHS staff, police and supermarket delivery drivers were cited as examples at the government announcement.

It meant some Norfolk schools were ringing parents yesterday, asking what their professions were, to establish how many children they should expect to still need to teach. Earlier in the week, some schools, anticipating closures, had been trying to draw up lists of which children were key workers. Others were asking parents to contact them as soon as possible to tell them.

There was frustration from some headteachers and school leaders at the lack of earlier notifications for schools - with the definitions still not made available as of the late afternoon.

Daniel Thrower, chief executive of the Wensum Trust, which runs schools including Hellesdon High School, Acle Academy and Alderman Peel High School, said, in a letter to parents on Thursday morning: “Schools had no prior warning and we have not been given any definitive information about closure. Currently, we do not know which professions are classed as key workers, or the exact definition of ‘vulnerable child’.”

More than 50 Norfolk schools were closed or partially closed on Thursday, amid staff shortages.

Norfolk County Council is working with schools to ensure the children of key workers can still be taught in the classroom. Schools believe some children are likely to have to go to schools other than their own, but attempts will be made to ensure some of their own school’s staff will be there, so familiar faces are around.

Children who have social workers and those with special needs and an education, health and care plan, will also continue to be taught.

Meanwhile, teenagers affected by the decision to cancel this summer’s GCSE and A-level exams could be awarded grades based on teacher assessment and the results of their mocks, it has been suggested.

And schools have been offering reassurance to students in Years 11 and 13, whose GCSE and A-Level examinations have been cancelled.

The government announced that GCSEs and A-levels will be cancelled - although prime minister Boris Johnson said there are plans for students to receive qualifications.

Education secretary Gavin Williamson said the government will be issuing guidance today as to how pupils unable to sit their GCSEs and A-levels because of the school closures will be awarded their grades.

He said there will be a “proper and fair system” of appeal for those who are unhappy with the results they are given.

He said: “We will be doing everything we can do to make sure they get their results in August as they will be hoping to, but we can’t predict as to how they are going to unfold,” he told BBC Radio 4’s Today programme.

School leaders said it is thought these proposed grades could be submitted to exam boards to check to ensure “consistency and fairness”.

Liz Wood, head of school at Sprowston Community Academy and Sixth Form, said: “We realise that the news that the exams will not happen in the summer will have a massive impact on our Y11 and Y13 students who gave worked so hard.

“At the moment, we are suggesting that they still access work as planned until we know any more details. The government has been asked to provide further clarity on this and we hope it will come swiftly to allay anxieties.”

Jo Philpott, headteacher of City of Norwich School, tweeted that she realised that year 11 and 13 pupils would be anxious about their GCSEs and A-levels and assemblies took place to share information and answer questions.

Alison Mobbs, principal of Lynn Grove Academy in Gorleston, said “no child must be disadvantaged” by the cancellation of exams.