More than 40,000 parents have signed a petition calling for a boycott of primary school tests, which are due to be taken later this month.
Parents supporting the Let Our Kids Be Kids campaign have complained of a damaging culture of over-testing.
Education Secretary Nicky Morgan says taking pupils out of school “even for a day is harmful to their education”.
It remains uncertain how many primary school children will be kept off school, but a social media campaign has been urging parents to take children on educational activities for the day.
The campaign organisers say children are “over-tested, over-worked and in a school system that places more importance on test results and league tables than children’s happiness and joy of learning”.
They have raised concerns about the impact of primary tests, so-called Sats tests, taken by seven-year-olds and 11-year-olds, which are being made more difficult.
They have challenged what they claim is a “dull, dry curriculum” based on tests.
In an open letter to the education secretary, campaigners have warned of schools becoming “exam factories” and that testing causes stress and can make young children feel like “failures”.
Fiona Robertson, a parent and primary teacher who is planning to take her children out of school, says that such tests can “turn children off” school.
She says that a narrow emphasis on testing and completing targets was taking away children’s creativity.
“They’re not producing really imaginative pieces. They’re too scared to,” she said.
‘It’s too hard’
Dawn Slater is keeping her six-year-old twins George and Josie away from lessons at Cheam Fields Primary School, Surrey on Tuesday. She said they had been stressed since returning to school this term.
Her son had been having tantrums and her daughter suffered nightmares.
“She’s been saying things like ‘I can’t do it, it’s too hard’, in her sleep,” she said.
“When I do the literacy test, it’s hard,” said Josie. “When we have the story, when we’re we’re stuck on a word, we can’t read it. So the story won’t make sense.”
Instead, the family is going to Nonsuch Park to “find birds, trees and insects”, Josie added.
But education minister Nick Gibb said tests improved standards.
He said: “Schools should not be putting pressure on young people when taking these assessments. I’ve been to many schools where the children don’t even know they’re taking the tests, they don’t have an effect on the children themselves because they have no consequences for the children.
They [the tests] are to hold schools to account, to make sure that every school in the country is equipping children with the knowledge and skills they need to succeed.”
And parent’s and teachers’ claims were dismissed by Chris McGovern, chairman of the Campaign for Real Education.
He said that any short-term stress was worth it if in the longer term it meant that children finished school with better results.
Mr. McGovern said that tests in England’s schools needed to be tougher to catch up with international competitors.
“We’re three years behind the Chinese at the age of 15. We are a bit of a basket case internationally.
“We’ve got to do something, we’ve got to act early, and a health check at seven is a good idea.”
Ministers have already had problems with the administration of primary school tests this year.
The baseline tests, which were intended to be a benchmark for measuring progress, were found to have unreliable results and have been postponed.
Tests for seven-year-olds in spelling, punctuation, and grammar also had to be called off when it was found that test questions had mistakenly been published on a Department of Education website.
Labour’s shadow education secretary Lucy Powell said she did not “condone children being taken out of school”.
But she accused the government of “creating chaos and confusion in primary assessment”.
Russell Hobby, the leader of the National Association of Head Teachers, said: “I think the gap between the profession and the government has never been wider than it is at the moment.”
He warned of “an enormous number of mistakes, delays and confusions around testing”.
But Ms. Morgan has argued that raising standards will improve creativity and not restrict it and keep children home, even for a day is harmful to their education.”