Nursery staff say they are being "treated like the bottom of the rung" after schools in England were told to shut to reduce the virus transmission.
Paul Trauberman, of Rainbow Smiles in Weston-super-Mare, said despite his staff being "scared" about the new Covid-19 variant they had come to work.
The government announced a strict lockdown across the country on Monday.
It was after the UK moved to Covid-19 threat level five, meaning there is a risk the NHS could be overwhelmed.
Mr Trauberman, who took over Rainbow Smiles nursery in 2016, said he felt conflicted.
"I've come in this morning and I've got staff crying and saying they are scared of this new variant."
'Staff feel insecure'
"We don't have PPE, we can't social distance, on the other hand we still have a business that is operational and we are not going bankrupt."
He said prolonged closure also carried the risk of going out of business but it was difficult to reassure staff when "you don't have any of the facts".
"One minute it is fine and the schools are going back, and two days later they are sending everyone home.
"It makes the staff feel insecure and... they just feel like they are being treated like the bottom of the rung.
"With this new variant ... they are having to deal with very close contact with children, with a virus around, which they are saying is very, very bad, but with no more information than that."
A Department for Education spokesperson 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."
'Keep people safe'
It said keeping nurseries open supported parents and delivered crucial education for children as Bristol mother-of-three Eleni Franklin has found.
She said she "really valued" Acorns Nursery in Henbury Hill, being open as she and her husband are both key workers - so their children, Allegra, five, Aria, two and Rafe nine-months-old, will attend school and nursery throughout the lockdown.
"I can see that nurseries are different to schools. There has been one case at Aria's nursery during this whole period, whereas in school there has been quite a few," she said.
"The nursery have been pretty good and although I understand there is a risk to staff, they have put a lot of measures in place to keep people safe."
One of the biggest challenges for nurseries - with some staff now unable to work because of their own childcare responsibilities - is maintaining child-to-staff ratios.
'Financial implications catastrophic'
Mr Trauberman said they worked on a basis of one-to-three for babies, one-to-four for under-three's and one-to-eight with under five-year-olds.
"We are trying to maintain these bubbles, but normally we would move staff around to accommodate highs and lows of staff and children, to balance it out, but we are unable to do that to enable these bubbles," he said.
His nursery is now identifying families that could potentially keep their children at home if they were unable to meet those ratios.
Mr Trauberman, who is a member of an online group for nursery owners, said some people were calling for nurseries to shut, but said if that happened they risked "not having a business to come back to".
"Small businesses are the backbone of the country and if a lot of those go under, the financial implications for the whole country are going to be catastrophic."
'Mental health suffered'
Mother-of-two Kara Willetts, from Tewkesbury in Gloucestershire, said she felt it was important her daughter Isobel continued going to nursery as she noticed her behaviour had changed when she had to stop going during the first lockdown in March.
"Isobel is a really sociable, outgoing child and she really suffered with not going in and seeing her friends during the first lockdown. Her mental health suffered and she displayed behaviour I had never seen from her before," she said.
Mrs Willetts said she had full confidence in the measures introduced at the nursery three-and-a-half-year-old Isobel attends in Cheltenham.
She said that with her husband working from home and a seven-month-old son also at home, the option of Isobel going to nursery was "beneficial to the whole family".
'Early Years not babysitting'
"It is quite difficult for my husband to concentrate on work with two kids at home. Transmission rates in young children are very low and if I had any safety concerns I wouldn't send Isobel there," she added.
Tom Shea, a former advisor to the Early Year's minister, said: "The biggest issue is that as a society we regard childcare as something like babysitting, rather than the start of the early year's development of learning.
"Sadly it seems the main reason for keeping us open is for protecting employment rather than protecting children."
Mr Shea owns Child First Nursery in Worksop and said he thought there was a "hierarchy" among key workers in terms of vaccination priorities. He said "sensibly" the first priority was NHS staff, followed by social carers for the elderly. He said teachers ranked a "reasonable" third, but that Early Years workers did not feature at all.
"They are expected just to work, and I am not sure if the government thinks that we are invisible," he said.
He called for early vaccination of Early Years workers to allow them to stay open and be protected.
"The irony now is that we are being told to keep open even though we are private businesses, we are dictated to about the funding we can receive and how we receive it… and if parents are frightened of their children going into the childcare setting then suddenly we don't get paid for that, so you find nurseries half empty being forced to open and it is not economical to do that."
A Department for Education spokesperson said: "We are funding nurseries as usual and all children are able to attend their early years setting in all parts of England.
"Working parents on coronavirus support schemes will still remain eligible for childcare support even if their income levels fall below the minimum requirement."