Children will return to the classroom this week after coronavirus crisis forced the closure of many schools for nearly six months.
Education Secretary Gavin Williamson warned parents that children risked a "huge dent in their future life chances" if they did not return to the classroom.
In a letter to parents, he said: "If a child is not in school, they stand to lose far more than just a few months of learning. It could well put a huge dent in their future life chances.
"Education is a birthright, so let's make sure we get all children back - back to learning, back to playing and back to being kids again."
But teaching unions reacted with fury when the Government published last-minute guidance for schools in lockdown areas - only days before pupils were due to go back for the new term.
Here are some of the changes in store for schools in England.
How will classrooms look different?
Desks will be arranged to face forward to prevent the spread of infection, rather than allowing children to sit facing each other at tables.
Windows and doors should be left open where possible to allow air to circulate.
There will be increased handwashing facilities and hand sanitiser available - with teachers told to supervise younger children when using sanitiser.
Social distancing to two metres should be followed whenever it is possible.
Children can bring their school bags with them but they should only have essential items such as books, lunch boxes and phones.
Teachers are told to avoid sharing equipment such as books and games between different groups - and rigorous cleaning measures should be in place.
What about communal areas?
Ministers ditched advice for "bubbles" of 15 pupils but classes or year groups should kept apart to prevent the spread of infection.
Many schools will have one-way systems in corridors, with staggered starts for lessons and for break times.
Masks can be worn in corridors and communal areas in secondary schools if headteachers wish but it is not mandatory.
Children should not wear masks in classrooms.
To prevent mixing between different groups, lunch could also be staggered, with some schools separating year groups and classes.
Will the curriculum be the same?
Schools have some freedom to help children catch up but the curriculum must remain "broad and ambitious".
The Government allows for "substantial modification" to the syllabus at the start of the year, with pupils allowed to drop some subjects in exceptional circumstances.
But schools should aim to be back to their normal curriculum by next summer.
There will be a ban on assemblies, collective worship and choirs - as there is an increased risk of infection from singing and shouting.
Music lessons should be restricted to groups of less than 15.
PE lessons can continue although outdoor sports should be the priority.
All equipment must be regularly cleaned.
Will children need to wear masks?
Secondary school pupils and staff can be told to wear face coverings in hallways and communal parts.
This becomes mandatory if the area is in local lockdown.
However masks are not advised in classrooms in any circumstances.
What happens if the school is in a lockdown area?
Under new rules, secondary schools pupils will be required to wears masks in communal areas in the first instance.
Heads must draw up plans for two week rota system for different groups, so pupils can spend a fortnight at home to see if symptoms emerge.
Week-on week-off rotas are also an option to keep children from mixing.
In the most extreme circumstances, all children will be sent home to study remotely again - with only the most vulnerable or children of key workers staying in school.
What if there is an outbreak at the school?
Schools will have to declare an outbreak if they have more than two coronavirus cases in two weeks or there has been a surge in pupils taking sick days where they might have coronavirus.
Heads can summon mobile testing units if they are worried about cases and schools have been given a small number of home testing kits to give to parents who may struggle to get their children tested.
However routine testing in schools is not advised.
Children who have been in close contact with a student with Covid-19 will have to self isolate at home.
The whole year group may have to isolate but the school does not have to close unless advised to by local health leaders.
Schools will be asked to keep a record of close contacts between staff and pupils in different groups - but no details have been given on how this would work in practice.
Temperature checks are optional, as the scientists do not think mass checks are an effective way of screening for coronavirus.
What if I'm worried about sending my child back to school?
Parents could face fines if they keep children at home as attendance will now be mandatory.
The official guidance says it is "vital for all children to return to school to minimise as far as possible the longer-term impact of the pandemic on children’s education, wellbeing and wider development".
Local authorities can fine parents if their child misses school.
Vulnerable children must go back to the classroom as the Government's shielding guidance has ended.
And what about Scotland, Wales and Northern Ireland?
Schools have already started to reopen in Scotland and Northern Ireland.
In Wales, state school pupils are due back in the classroom from the start of September - with all pupils expected to be accommodated by September 14.
Different rules apply for schools in each of the devolved administrations.
New school rules in brief
Bubbles: Children will be in bubbles so they do not mix with fellow pupils from other year groups.
Gatherings: Assemblies and acts of worship with the whole school will not take place.
Eating: Children will have lunch in classrooms rather than the hall or dining area. Those who get school meals will also eat at their desks in the classroom.
Masks: Must be worn in corridors at secondary schools. Not compulsory in primaries.
Parents: Cannot enter the school for assemblies or concerts.
Trips: No school trips or outings while Covid rules are in place.
After school: Extra-curricular activities and sports after school are banned.
Sports: Can take place in bubbles but sports days are forbidden.
PE: Children doing physical education must arrive at school in their kit so they do not get changed on the school premises.
Travel: Frequent cleaning of school buses, ventilation through open windows and face coverings. Staggered school start times. Face coverings compulsory on public transport for ages 11+. Does not apply to dedicated school transport, except in Scotland.
