Many schools are shutting their gates until further notice as the government ramps up measures to stop the spread of coronavirus.
The Department for Education has published a list of "key workers" deemed "essential" to the COVID-19 response and whose children will continue to be cared for at school amid the pandemic.
It said: "The most recent scientific advice on how to further limit the spread of COVID-19 is clear. If children can stay safely at home, they should, to limit the chance of the virus spreading.
"That is why the government has asked parents to keep their children at home, wherever possible, and asked schools to remain open only for those children who absolutely need to attend."
But the department added: "If your work is critical to the COVID-19 response, or you work in one of the critical sectors listed below, and you cannot keep your child safe at home then your children will be prioritised for education provision," the Department for Education said.
The list has been separated into eight categories:
Health and social care
Includes frontline health and social care staff - such as doctors, nurses, midwives, paramedics, as well as support and specialist staff in the health and social care sector. In addition, those working in supply chains, including producers and distributors of medicines and personal protective equipment, are included.
Education and childcare
Includes nursery, teaching staff and social workers, as the department said these workers are required to deliver their plans.
Key public services
Those required to run the justice system, religious staff, as well as those responsible for managing the deceased and journalists providing public service broadcasting are on the list.
Local and national government
The list "only includes administrative occupations essential to the effective delivery of the COVID-19 response or delivering essential public services", including payment of benefits.
Food and other necessary goods
Includes those involved in the production, processing, distribution, sale and delivery of food.
Public safety and national security
Police, support staff, Ministry of Defence civilian staff and armed forces personnel are on the list, along with fire and rescue staff, as well as those responsible for border security, prison and probation staff.
Includes those who will keep "air, water, road and rail passenger and freight transport modes operating during the COVID-19 response".
Utilities, communication and financial services
Staff required to keep oil, gas, electricity, water and sewerage operations running are on the list, along with those in the civil nuclear, chemical and telecommunications sectors. Those in postal services and working to provide essential financial services provision are also included.
The parents of vulnerable children are the other group of people allowed to continue sending their children to school.
The government says this group will include those who have a social worker and those with Education, Health and Care Plans - a legal document that describes a child's special educational needs and the support they require.
Many schools in England will shut their gates on Friday until further notice, as will nurseries, colleges and childminders.
In Scotland and Wales, all schools will have closed by Friday, and schools in Northern Ireland are due to shut from Monday.
Special schools are to remain open during the closures, while educational settings will continue to cater for vulnerable children and pupils whose parents are key workers.
The "key workers" list was expected to be published on Thursday but was delayed until Friday morning - prompting criticism.
The Early Years Alliance acknowledged it comes during "incredibly challenging times", but said that a delay in establishing who would be able to access childcare from Monday would make an "already difficult task near-impossible".