Brighton and Hove Council has become the first in the country to defy the Government over nurseries after it told all early years providers under its control to close from Thursday.
The council said that the six nurseries under its direct control should shut their doors to all but the children of key workers and the most vulnerable toddlers.
The decision has been made to protect staff, families and children and help reduce the spread of coronavirus in the city, the council said.
The Government has said that nurseries should remain open to all children during the national lockdown while primary and secondary schools have been told to move to remote learning.
But council chiefs at Brighton and Hove said they have taken the decision to close nurseries in response to concerns from their staff about rising infection rates in the city.
Cllr Hannah Clare wrote to Vicky Ford, an education minister, saying: “We believe the same data and science that led to a school closure also applies to the early years sector.
“Many early years providers in our city that we have spoken to have expressed that they feel a huge responsibility for their staff safety at this time more than ever. They feel it is the right thing for them to close to all but vulnerable children and the children of key workers.”
Cllr Clare asked the Government to provide extra funding for nurseries which are closing since it will result in them suffering financially. She said that closing the nurseries is a temporary measure and that they hope to open them again as soon as possible.
Meanwhile, the Early Years Alliance (EYA) has said that a number of nurseries across England have taken the decision to partially close amid concerns about coronavirus transmission risks.
Several nursery heads have taken the decision to only open their doors to children of key workers or vulnerable children amid safety fears, according to the charity.
Early years leaders say there is fear and confusion over how safe the settings are and they have demanded reassurance from the Government on the evidence behind the decision to keep nurseries open.
But vaccine minister Nadhim Zahawi has insisted that nurseries present "very little risk".
Unions have called on the Government to reconsider its decision to keep nurseries and pre-schools open to all children amid concerns over the new Covid-19 strain.
Stuart Fegan, national officer at the union GMB, said: "There is no scientific evidence to support the continued opening of nurseries. It is purely a political decision, made by ministers who are failing to take their responsibility to staff, families and the wider community seriously enough.
"They’ve left nursery staff, childminders and nannies worrying for their safety and sown fear and confusion among parents. It’s time for the Government to step in and correct this dangerous mistake by closing all nursery and pre-school provision to all but key workers and vulnerable children, in line with school closures. "
A Department for Education spokeswoman said: "Early years settings remain low risk environments for children and staff and there is no evidence that the new variant of coronavirus disproportionately affects young children.
"Keeping nurseries and childminders open will support parents and deliver the crucial care and education for our youngest children."
Evidence suggests pre-school children are less susceptible to infection and are not playing a driving role in transmission, the DfE added.