Schools should not limit the number of children of critical workers who can attend during the national lockdown, new Department for Education guidance says.
The DfE has also encouraged schools to work with each other, education providers and other local organisations to ensure that face- to-face provision is provided for vulnerable children.
But the guidance also urges parents who are critical workers to keep their children at home if they can.
The new guidance, published by the department today, two days after the coronavirus lockdown began, comes amid concerns that more pupils will be attending school this time around.
Schools are remaining open during the lockdown to vulnerable children and those of critical workers.
Coronavirus: More pupils eligible to attend school
The government has extended the criteria for pupils who can attend schools to include children who are unable to access remote learning at home.
But school leaders have warned that because many schools have been unable to obtain their allocation of DfE laptops, more pupils will need to attend.
The new guidance says: "We know that every school will have a different number of children of critical workers who need to attend.
"It is important that on-site provision is provided for these pupils, and there is no limit to numbers of these pupils who may attend and schools should not limit attendance of these groups.
"This is because we are reducing overall social contact across areas and the country rather than individually by each institution."
It adds that "limiting attendance does not suggest that schools and colleges have become significantly less safe for young people. Instead limiting attendance is about supporting the reduction of the overall number of social contacts in our communities."
The DfE has encouraged schools to work with each other, with other education providers, local authorities, social workers, police, youth services and key workers " to maximise opportunities for face-to-face provision for vulnerable children."
Tes reported earlier today that there are concerns that the numbers of pupils in schools could undermine the attempts to stop the spread of the coronavirus through the national lockdown.
It has been reported today that Norfolk County Council has said it is working with education leaders in the region to develop a prioritisation criteria for school places after many families have requested places during the lockdown.
The council said it is likely that in some schools this will mean both parents are expected to be key workers, with priority given to those whose parents work in emergency life-saving services.